Allies and Morrison LLP is an architecture and urban planning practice based in London and Cambridge. Founded in 1984, the practice is now one of Britain's largest architectural firms. The practice's work ranges from architecture and interior design to conservation and renovation of historic buildings to urbanism, planning, consultation and research. The firm's notable projects include the redevelopment of the Royal Festival Hall, the masterplan for the Queen Elizabeth Olympic Park, BBC Media Village and the redevelopment of King's Cross Central. The practice has a reputation for designing modernist, yet stylistically restrained buildings.

They have completed projects throughout the UK, and in Ireland, India, Africa and the Middle East and in North America. The practice's portfolio includes cultural, educational, public and housing projects.