Tŷ Hywel (Cardiff)

 national government / government, administrative building

Tŷ Hywel (English: Howell's House) is named after Hywel Dda (Hywel the Good) and is used by the National Assembly for Wales, Cardiff, Wales. Previously it was known as Crickhowell House (Welsh: Tŷ Crughywel) and was named after Lord Crickhowell.

It is also informally known as the Assembly Office and houses Assembly Members of the National Assembly for Wales and their staff, and staff of the Assembly Commission. The Welsh Government also operates from the building and occupies one floor. It is leased by the National Assembly for Wales under the Government of Wales Act 1998.

It was opened in 1993 and has a total floor area of 11,583 m (38,002 ft). It is a red-brick building and is connected to the Senedd debating chamber in Cardiff Bay, Wales. The building has previously been used as temporary debating chamber for the National Assembly for Wales from 1999 until the Senedd was opened in 2006.

On 25 June 2008, the Prince of Wales officially opened Siambr Hywel, the National Assembly's youth debating chamber and education centre. It is based in the former debating chamber in Tŷ Hywel, which was used until the Senedd next door was built.