Howell's School is an independent day school for girls in Llandaff, a district in northern Cardiff, Wales. It consists of a nursery, infants, junior, senior school and a sixth form. The sixth form became coeducational in September 2005 and was renamed Howell's Co-ed College.

Llandaff is a district, community and coterminous electoral ward in the north of Cardiff, capital of Wales. It was incorporated into the city in 1922. It is the seat of the Bishop of Llandaff, whose diocese within the Church in Wales covers the most populous area of Wales.