St Stephen's Chapel, sometimes called the Royal Chapel of St Stephen, was a chapel in the old Palace of Westminster which served as the chamber of the House of Commons of England and that of Great Britain from 1547 to 1834. It was largely destroyed in the fire of 1834, but the Chapel of St Mary Undercroft in the crypt survived.

The present-day St Stephen's Hall and its porch, which are within the new Palace of Westminster built in the 19th century, stand on exactly the same site and are today accessed through the St Stephen's Entrance, the public entrance of the House of Commons.