diff --git a/forum/api/comments.py b/forum/api/comments.py
index 38a9a8bd..429277db 100644
--- a/forum/api/comments.py
+++ b/forum/api/comments.py
@@ -220,12 +220,14 @@ def update_comment(
         raise error
 
 
-def delete_comment(comment_id: str, course_id: Optional[str] = None) -> dict[str, Any]:
+def delete_comment(comment_id: str, course_id: Optional[str] = None, deleted_by: Optional[str] = None) -> dict[str, Any]:
     """
     Delete a comment.
 
     Parameters:
         comment_id: The ID of the comment to be deleted.
+        course_id: The ID of the course (optional).
+        deleted_by: The ID of the user performing the delete (optional).
     Body:
         Empty.
     Response:
@@ -244,7 +246,9 @@ def delete_comment(comment_id: str, course_id: Optional[str] = None) -> dict[str
         backend,
         exclude_fields=["endorsement", "sk"],
     )
-    backend.delete_comment(comment_id)
+    # Soft delete comment instead of hard delete
+    backend.soft_delete_comment(comment_id, deleted_by)
+    # backend.delete_comment(comment_id)
     author_id = comment["author_id"]
     comment_course_id = comment["course_id"]
     parent_comment_id = data["parent_id"]
diff --git a/forum/api/threads.py b/forum/api/threads.py
index 5eb60768..4ba8ce0b 100644
--- a/forum/api/threads.py
+++ b/forum/api/threads.py
@@ -159,12 +159,14 @@ def get_thread(
         raise ForumV2RequestError("Failed to prepare thread API response") from error
 
 
-def delete_thread(thread_id: str, course_id: Optional[str] = None) -> dict[str, Any]:
+def delete_thread(thread_id: str, course_id: Optional[str] = None, deleted_by: Optional[str] = None) -> dict[str, Any]:
     """
     Delete the thread for the given thread_id.
 
     Parameters:
         thread_id: The ID of the thread to be deleted.
+        course_id: The ID of the course (optional).
+        deleted_by: The ID of the user performing the delete (optional).
     Response:
         The details of the thread that is deleted.
     """
@@ -177,7 +179,9 @@ def delete_thread(thread_id: str, course_id: Optional[str] = None) -> dict[str,
             f"Thread does not exist with Id: {thread_id}"
         ) from exc
 
-    backend.delete_comments_of_a_thread(thread_id)
+    # Soft delete comments and thread instead of hard delete
+    backend.soft_delete_comments_of_a_thread(thread_id, deleted_by)
+    # backend.delete_comments_of_a_thread(thread_id)
     thread = backend.validate_object("CommentThread", thread_id)
 
     try:
@@ -187,7 +191,9 @@ def delete_thread(thread_id: str, course_id: Optional[str] = None) -> dict[str,
         raise ForumV2RequestError("Failed to prepare thread API response") from error
 
     backend.delete_subscriptions_of_a_thread(thread_id)
-    result = backend.delete_thread(thread_id)
+    # Soft delete thread instead of hard delete
+    result = backend.soft_delete_thread(thread_id, deleted_by)
+    # result = backend.delete_thread(thread_id)
     if result and not (thread["anonymous"] or thread["anonymous_to_peers"]):
         backend.update_stats_for_course(
             thread["author_id"], thread["course_id"], threads=-1
diff --git a/forum/backends/mongodb/api.py b/forum/backends/mongodb/api.py
index cddc412d..e7eb3763 100644
--- a/forum/backends/mongodb/api.py
+++ b/forum/backends/mongodb/api.py
@@ -596,6 +596,7 @@ def handle_threads_query(
         base_query: dict[str, Any] = {
             "_id": {"$in": comment_thread_obj_ids},
             "context": context,
+            "is_deleted": {"$ne": True},  # Exclude soft deleted threads
         }
 
         # Group filtering
@@ -1495,6 +1496,9 @@ def get_user_by_username(username: str | None) -> dict[str, Any] | None:
     def get_comment(comment_id: str) -> dict[str, Any] | None:
         """Get comment from id."""
         comment = Comment().get(comment_id)
+        # Return None if comment is soft deleted
+        if comment and comment.get('is_deleted'):
+            return None
         return comment
 
     @staticmethod
@@ -1503,6 +1507,9 @@ def get_thread(thread_id: str) -> dict[str, Any] | None:
         thread = CommentThread().get(thread_id)
         if not thread:
             return None
+        # Return None if thread is soft deleted
+        if thread.get('is_deleted'):
+            return None
         return thread
 
     @staticmethod
@@ -1568,6 +1575,42 @@ def delete_thread(thread_id: str) -> int:
         """Delete thread."""
         return CommentThread().delete(thread_id)
 
+    @staticmethod
+    def soft_delete_thread(thread_id: str, deleted_by: str = None) -> int:
+        """Soft delete thread by marking it as deleted."""
+        return CommentThread().update(
+            thread_id, 
+            is_deleted=True, 
+            deleted_at=datetime.now(), 
+            deleted_by=deleted_by
+        )
+
+    @staticmethod
+    def soft_delete_comments_of_a_thread(thread_id: str, deleted_by: str = None) -> None:
+        """Soft delete all comments of a thread by marking them as deleted."""
+        deleted_at = datetime.now()
+        for comment in Comment().get_list(
+            comment_thread_id=ObjectId(thread_id),
+            depth=0,
+            parent_id=None,
+        ):
+            Comment().update(
+                comment["_id"], 
+                is_deleted=True, 
+                deleted_at=deleted_at, 
+                deleted_by=deleted_by
+            )
+
+    @staticmethod
+    def soft_delete_comment(comment_id: str, deleted_by: str = None) -> None:
+        """Soft delete comment by marking it as deleted."""
+        Comment().update(
+            comment_id, 
+            is_deleted=True, 
+            deleted_at=datetime.now(), 
+            deleted_by=deleted_by
+        )
+
     @staticmethod
     def create_thread(data: dict[str, Any]) -> str:
         """Create thread."""
@@ -1723,7 +1766,35 @@ def get_paginated_user_stats(
     @staticmethod
     def get_contents(**kwargs: Any) -> list[dict[str, Any]]:
         """Return contents."""
-        return list(Contents().get_list(**kwargs))
+        # Add soft delete filtering
+        kwargs['is_deleted'] = {'$ne': True}
+        contents = list(Contents().get_list(**kwargs))
+        
+        # Get all thread IDs mentioned in comments
+        comment_thread_ids = set()
+        for content in contents:
+            if content.get('_type') == 'Comment' and content.get('comment_thread_id'):
+                comment_thread_ids.add(content['comment_thread_id'])
+        
+        # Get all deleted thread IDs in one query
+        deleted_thread_ids = set()
+        if comment_thread_ids:
+            deleted_threads = CommentThread()._collection.find(
+                {"_id": {"$in": list(comment_thread_ids)}, "is_deleted": True},
+                {"_id": 1}
+            )
+            deleted_thread_ids = {thread['_id'] for thread in deleted_threads}
+        
+        # Filter out comments that belong to deleted threads
+        filtered_contents = []
+        for content in contents:
+            if content.get('_type') == 'Comment':
+                thread_id = content.get('comment_thread_id')
+                if thread_id and thread_id in deleted_thread_ids:
+                    continue  # Skip comment if its thread is deleted
+            filtered_contents.append(content)
+        
+        return filtered_contents
 
     @staticmethod
     def get_user_thread_filter(course_id: str) -> dict[str, Any]:
@@ -1731,6 +1802,7 @@ def get_user_thread_filter(course_id: str) -> dict[str, Any]:
         return {
             "_type": {"$in": [CommentThread.content_type]},
             "course_id": {"$in": [course_id]},
+            "is_deleted": {"$ne": True},  # Exclude soft deleted threads
         }
 
     @staticmethod
diff --git a/forum/backends/mongodb/comments.py b/forum/backends/mongodb/comments.py
index 7f9af685..1f6f2a9e 100644
--- a/forum/backends/mongodb/comments.py
+++ b/forum/backends/mongodb/comments.py
@@ -62,6 +62,9 @@ def doc_to_hash(cls, doc: dict[str, Any]) -> dict[str, Any]:
             "created_at": doc.get("created_at"),
             "updated_at": doc.get("updated_at"),
             "title": doc.get("title"),
+            "is_deleted": doc.get("is_deleted", False),
+            "deleted_at": doc.get("deleted_at"),
+            "deleted_by": doc.get("deleted_by"),
         }
 
     def insert(
@@ -166,6 +169,9 @@ def update(
         endorsement_user_id: Optional[str] = None,
         sk: Optional[str] = None,
         is_spam: Optional[bool] = None,
+        is_deleted: Optional[bool] = None,
+        deleted_at: Optional[datetime] = None,
+        deleted_by: Optional[str] = None,
     ) -> int:
         """
         Updates a comment document in the database.
@@ -210,6 +216,9 @@ def update(
             ("closed", closed),
             ("sk", sk),
             ("is_spam", is_spam),
+            ("is_deleted", is_deleted),
+            ("deleted_at", deleted_at),
+            ("deleted_by", deleted_by),
         ]
         update_data: dict[str, Any] = {
             field: value for field, value in fields if value is not None
diff --git a/forum/backends/mongodb/threads.py b/forum/backends/mongodb/threads.py
index 61126624..cea2dae5 100644
--- a/forum/backends/mongodb/threads.py
+++ b/forum/backends/mongodb/threads.py
@@ -81,6 +81,9 @@ def doc_to_hash(cls, doc: dict[str, Any]) -> dict[str, Any]:
             "author_id": doc.get("author_id"),
             "group_id": doc.get("group_id"),
             "thread_id": str(doc.get("_id")),
+            "is_deleted": doc.get("is_deleted", False),
+            "deleted_at": doc.get("deleted_at"),
+            "deleted_by": doc.get("deleted_by"),
         }
 
     def insert(
@@ -208,6 +211,9 @@ def update(
         group_id: Optional[int] = None,
         skip_timestamp_update: bool = False,
         is_spam: Optional[bool] = None,
+        is_deleted: Optional[bool] = None,
+        deleted_at: Optional[datetime] = None,
+        deleted_by: Optional[str] = None,
     ) -> int:
         """
         Updates a thread document in the database.
@@ -262,6 +268,9 @@ def update(
             ("closed_by_id", closed_by_id),
             ("group_id", group_id),
             ("is_spam", is_spam),
+            ("is_deleted", is_deleted),
+            ("deleted_at", deleted_at),
+            ("deleted_by", deleted_by),
         ]
         update_data: dict[str, Any] = {
             field: value for field, value in fields if value is not None
diff --git a/forum/backends/mysql/api.py b/forum/backends/mysql/api.py
index c8633476..110176ef 100644
--- a/forum/backends/mysql/api.py
+++ b/forum/backends/mysql/api.py
@@ -653,7 +653,7 @@ def handle_threads_query(
                 raise ValueError("User does not exist") from exc
         # Base query
         base_query = CommentThread.objects.filter(
-            pk__in=mysql_comment_thread_ids, context=context
+            pk__in=mysql_comment_thread_ids, context=context, is_deleted=False  # Exclude soft deleted threads
         )
 
         # Group filtering
@@ -986,6 +986,15 @@ def delete_comments_of_a_thread(thread_id: str) -> None:
         """Delete comments of a thread."""
         Comment.objects.filter(comment_thread__pk=thread_id, parent=None).delete()
 
+    @staticmethod
+    def soft_delete_comments_of_a_thread(thread_id: str, deleted_by: str = None) -> None:
+        """Soft delete comments of a thread by marking them as deleted."""
+        Comment.objects.filter(comment_thread__pk=thread_id, parent=None).update(
+            is_deleted=True,
+            deleted_at=timezone.now(),
+            deleted_by=deleted_by
+        )
+
     @classmethod
     def delete_subscriptions_of_a_thread(cls, thread_id: str) -> None:
         """Delete subscriptions of a thread."""
@@ -1450,7 +1459,7 @@ def find_or_create_user(
     def get_comment(comment_id: str) -> dict[str, Any] | None:
         """Return comment from comment_id."""
         try:
-            comment = Comment.objects.get(pk=comment_id)
+            comment = Comment.objects.get(pk=comment_id, is_deleted=False)  # Exclude soft deleted comments
         except Comment.DoesNotExist:
             return None
         return comment.to_dict()
@@ -1530,6 +1539,15 @@ def delete_comment(cls, comment_id: str) -> None:
 
         comment.delete()
 
+    @staticmethod
+    def soft_delete_comment(comment_id: str, deleted_by: str = None) -> None:
+        """Soft delete comment by marking it as deleted."""
+        comment = Comment.objects.get(pk=comment_id)
+        comment.is_deleted = True
+        comment.deleted_at = timezone.now()
+        comment.deleted_by = deleted_by
+        comment.save()
+
     @staticmethod
     def get_commentables_counts_based_on_type(course_id: str) -> dict[str, Any]:
         """Return commentables counts in a course based on thread's type."""
@@ -1716,7 +1734,7 @@ def get_user(user_id: str, get_full_dict: bool = True) -> dict[str, Any] | None:
     def get_thread(thread_id: str) -> dict[str, Any] | None:
         """Return thread from thread_id."""
         try:
-            thread = CommentThread.objects.get(pk=thread_id)
+            thread = CommentThread.objects.get(pk=thread_id, is_deleted=False)  # Exclude soft deleted threads
         except CommentThread.DoesNotExist:
             return None
         return thread.to_dict()
@@ -1771,6 +1789,19 @@ def delete_thread(thread_id: str) -> int:
         thread.delete()
         return 1
 
+    @staticmethod
+    def soft_delete_thread(thread_id: str, deleted_by: str = None) -> int:
+        """Soft delete thread by marking it as deleted."""
+        try:
+            thread = CommentThread.objects.get(pk=thread_id)
+        except ObjectDoesNotExist:
+            return 0
+        thread.is_deleted = True
+        thread.deleted_at = timezone.now()
+        thread.deleted_by = deleted_by
+        thread.save()
+        return 1
+
     @staticmethod
     def create_thread(data: dict[str, Any]) -> str:
         """Create thread."""
@@ -1911,14 +1942,14 @@ def update_thread(
     @staticmethod
     def get_user_thread_filter(course_id: str) -> dict[str, Any]:
         """Get user thread filter"""
-        return {"course_id": course_id}
+        return {"course_id": course_id, "is_deleted": False}  # Exclude soft deleted threads
 
     @staticmethod
     def get_filtered_threads(
         query: dict[str, Any], ids_only: bool = False
     ) -> list[dict[str, Any]]:
         """Return a list of threads that match the given filter."""
-        threads = CommentThread.objects.filter(**query)
+        threads = CommentThread.objects.filter(**query).filter(is_deleted=False)  # Exclude soft deleted threads
         if ids_only:
             return [{"_id": str(thread.pk)} for thread in threads]
         return [thread.to_dict() for thread in threads]
@@ -2158,8 +2189,11 @@ def get_contents(**kwargs: Any) -> list[dict[str, Any]]:
             key: value for key, value in kwargs.items() if hasattr(CommentThread, key)
         }
 
-        comments = Comment.objects.filter(**comment_filters)
-        threads = CommentThread.objects.filter(**thread_filters)
+        comments = Comment.objects.filter(**comment_filters).filter(
+            is_deleted=False,  # Exclude soft deleted comments
+            comment_thread__is_deleted=False  # Exclude comments on deleted threads
+        )
+        threads = CommentThread.objects.filter(**thread_filters).filter(is_deleted=False)  # Exclude soft deleted threads
 
         sort_key = kwargs.get("sort_key")
         if sort_key:
diff --git a/forum/backends/mysql/models.py b/forum/backends/mysql/models.py
index e149daa6..d87f045a 100644
--- a/forum/backends/mysql/models.py
+++ b/forum/backends/mysql/models.py
@@ -129,6 +129,25 @@ class Content(models.Model):
         default=False,
         help_text="Whether this content has been identified as spam by AI moderation",
     )
+    is_deleted: models.BooleanField[bool, bool] = models.BooleanField(
+        default=False,
+        help_text="Whether this content has been soft deleted",
+    )
+    deleted_at: models.DateTimeField[Optional[datetime], datetime] = (
+        models.DateTimeField(
+            null=True,
+            blank=True,
+            help_text="When this content was soft deleted",
+        )
+    )
+    deleted_by: models.ForeignKey[User, User] = models.ForeignKey(
+        User,
+        related_name="deleted_%(class)s",
+        null=True,
+        blank=True,
+        on_delete=models.SET_NULL,
+        help_text="User who soft deleted this content",
+    )
     uservote = GenericRelation(
         "UserVote",
         object_id_field="content_object_id",
@@ -267,8 +286,8 @@ class CommentThread(Content):
 
     @property
     def comment_count(self) -> int:
-        """Return the number of comments in the thread."""
-        return Comment.objects.filter(comment_thread=self).count()
+        """Return the number of comments in the thread (excluding deleted)."""
+        return Comment.objects.filter(comment_thread=self, is_deleted=False).count()
 
     @classmethod
     def get(cls, thread_id: str) -> CommentThread:
@@ -323,6 +342,9 @@ def to_dict(self) -> dict[str, Any]:
             "edit_history": edit_history,
             "group_id": self.group_id,
             "is_spam": self.is_spam,
+            "is_deleted": self.is_deleted,
+            "deleted_at": self.deleted_at,
+            "deleted_by": str(self.deleted_by.pk) if self.deleted_by else None,
         }
 
     def doc_to_hash(self) -> dict[str, Any]:
@@ -509,6 +531,9 @@ def to_dict(self) -> dict[str, Any]:
             "created_at": self.created_at,
             "endorsement": endorsement if self.endorsement else None,
             "is_spam": self.is_spam,
+            "is_deleted": self.is_deleted,
+            "deleted_at": self.deleted_at,
+            "deleted_by": str(self.deleted_by.pk) if self.deleted_by else None,
         }
         if edit_history:
             data["edit_history"] = edit_history
diff --git a/forum/serializers/contents.py b/forum/serializers/contents.py
index 6fd174b7..bb4dcbd7 100644
--- a/forum/serializers/contents.py
+++ b/forum/serializers/contents.py
@@ -78,6 +78,9 @@ class ContentSerializer(serializers.Serializer[dict[str, Any]]):
     closed = serializers.BooleanField(default=False)
     type = serializers.CharField()
     is_spam = serializers.BooleanField(default=False)
+    is_deleted = serializers.BooleanField(default=False)
+    deleted_at = CustomDateTimeField(allow_null=True, required=False)
+    deleted_by = serializers.CharField(allow_null=True, required=False)
 
     def create(self, validated_data: dict[str, Any]) -> Any:
         """Raise NotImplementedError"""
diff --git a/forum/views/comments.py b/forum/views/comments.py
index ed90507c..21016bef 100644
--- a/forum/views/comments.py
+++ b/forum/views/comments.py
@@ -142,7 +142,7 @@ def delete(self, request: Request, comment_id: str) -> Response:
             request (Request): The incoming request.
             comment_id: The ID of the comment to be deleted.
         Body:
-            Empty.
+            deleted_by: Optional ID of the user performing the delete (defaults to authenticated user).
         Response:
             The details of the comment that is deleted.
         """