Will Alsop (born 1947) is an English architect based in London, responsible for several distinctive and controversial modernist buildings — most in the United Kingdom. Alsop's buildings are usually distinguished by their vibrant use of bright color and unusual forms. While Alsop has won praise from some critics and fans of avant garde architecture, he has also faced criticism from fellow architects and some segments of the general public.

Alsop studied at the Architectural Association School of Architecture and set up a practice (Alsop & Lyall) with fellow student John Lyall in Hammersmith in 1981, subsequently renamed Alsop & Stormer in 1991.

His plans for a "Fourth Grace" to be built on Liverpool's Pier Head waterfront — the so-called "Cloud building" — were cancelled in June 2004, officially because of rising costs and unrealistic design. Many suspect the design's lack of support among the people of Liverpool lead to its cancellation.

Alsop's architectural talents may be the subject of controversy, but he has managed to build up an international reputation and a certain degree of fame (despite the fact that he has designed relatively few buildings).

His credits include:

• Hamburg Ferry Terminal
• Cardiff Bay Visitors Centre
• Peckham Library — winner of the Stirling Prize in 2000
• North Greenwich tube station
• Ontario College of Art & Design — Sharpe Centre for Design