diff --git a/backend/alembic/versions/0079_add_rom_files_rom_id_index.py b/backend/alembic/versions/0079_add_rom_files_rom_id_index.py
new file mode 100644
index 000000000..14613655b
--- /dev/null
+++ b/backend/alembic/versions/0079_add_rom_files_rom_id_index.py
@@ -0,0 +1,30 @@
+"""Add index on rom_id for rom_files table
+
+Revision ID: 0079_add_rom_files_rom_id_index
+Revises: 0078_add_libretro_id_to_roms
+Create Date: 2026-04-14 00:00:00.000000
+
+"""
+
+from alembic import op
+
+# revision identifiers, used by Alembic.
+revision = "0079_add_rom_files_rom_id_index"
+down_revision = "0078_add_libretro_id_to_roms"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    with op.batch_alter_table("rom_files", schema=None) as batch_op:
+        batch_op.create_index(
+            "idx_rom_files_rom_id",
+            ["rom_id"],
+            unique=False,
+            if_not_exists=True,
+        )
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("rom_files", schema=None) as batch_op:
+        batch_op.drop_index("idx_rom_files_rom_id", if_exists=True)
diff --git a/backend/models/rom.py b/backend/models/rom.py
index 9e8a67e93..88fd257d8 100644
--- a/backend/models/rom.py
+++ b/backend/models/rom.py
@@ -64,6 +64,8 @@ class SiblingRom(BaseModel):
 class RomFile(BaseModel):
     __tablename__ = "rom_files"
 
+    __table_args__ = (Index("idx_rom_files_rom_id", "rom_id"),)
+
     id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
     rom_id: Mapped[int] = mapped_column(ForeignKey("roms.id", ondelete="CASCADE"))
     file_name: Mapped[str] = mapped_column(String(length=FILE_NAME_MAX_LENGTH))