diff --git a/github/core/http.py b/github/core/http.py
index d4befcc4..68fcbe91 100644
--- a/github/core/http.py
+++ b/github/core/http.py
@@ -19,6 +19,7 @@
     from github.interfaces import Node, Resource
     from github.interfaces.assignable import AssignableData
     from github.interfaces.labelable import LabelableData
+    from github.interfaces.reactable import ReactableData
     from github.interfaces.starrable import StarrableData
     from github.interfaces.subscribable import SubscribableData
     from github.organization.organization import OrganizationData
@@ -1785,6 +1786,24 @@ async def mutate_labelable_remove_labels(
 
         return data  # type: ignore
 
+    async def mutate_reactable_add_reaction(
+        self: Self,
+        /,
+        reactable_id: str,
+        content: str,
+        *,
+        reactable_fields: Iterable[str] = MISSING,
+        reaction_fields: Iterable[str] = MISSING,
+    ) -> tuple[ReactableData, ReactionData]:
+        reactable_fields = ("__typename",) if reactable_fields is MISSING else reactable_fields
+        reaction_fields = github.utility.get_merged_graphql_fields(github.Reaction, reaction_fields)
+        query = "mutation($reactable_id:ID!,$content:ReactionContent!,$mutation_id:String!){addReaction(input:{clientMutationId:$mutation_id,subjectId:$reactable_id,content:$content}){subject{%s},reaction{%s}}}" % (",".join(reactable_fields), ",".join(reaction_fields))
+        path = ("addReaction",)
+
+        data = await self._mutate(query, *path, reactable_id=reactable_id, content=content)
+
+        return (data["subject"], data["reaction"])  # type: ignore
+
     async def mutate_starrable_star(
         self: Self,
         /,
diff --git a/github/interfaces/reactable.py b/github/interfaces/reactable.py
index 3ba5aff3..ffaca72a 100644
--- a/github/interfaces/reactable.py
+++ b/github/interfaces/reactable.py
@@ -5,7 +5,7 @@
     from typing_extensions import Self
 
     from github.connection import Connection, ReactionOrder
-    from github.content import Reaction
+    from github.content import Reaction, ReactionContent
     from github.interfaces import Node
 
 import github
@@ -156,6 +156,46 @@ def fetch_reactions(
             reverse=reverse if reverse is not MISSING else False,
         )
 
+    async def add_reaction(
+        self: Self,
+        content: ReactionContent,
+        /,
+    ) -> Reaction:
+        """
+        |coro|
+
+        Adds a reaction to the reactable.
+
+
+        .. note::
+
+            Use of this mutation will also update the following fields:
+
+            - :attr:`~.reaction_count`
+
+
+        Parameters
+        ----------
+
+        content: :class:`~github.ReactionContent`
+            The content of the reaction.
+
+
+        :rtype: :class:`~github.Reaction`
+        """
+
+        if TYPE_CHECKING and not isinstance(self, Node):
+            raise NotImplementedError
+
+        reactable_data, reaction_data = await self._http.mutate_reactable_add_reaction(self.id, content.value, reactable_fields=("reactions{totalCount}",))
+
+        if "reactions" not in self._data.keys():
+            self._data["reactions"] = dict()  # type: ignore
+
+        self._data["reactions"]["totalCount"] = reactable_data["reactions"]["totalCount"]
+
+        return github.Reaction._from_data(reaction_data, http=self._http)
+
 
 __all__ = [
     "Reactable",