Lawes, William  ( baptized May 1, 1602 , Salisbury, Wiltshire, England—died September Sept. 24, 1645 , Chester, Cheshire )  English composer, prominent during the early Baroque period, noted for his highly original instrumental music.

The brother of the composer Henry Lawes, he entered the household of the earl of Hertford about 1612 and in 1635 became a musician to Charles I. Lawes fought with the Royalists during the English Civil Wars (1642–51) and was killed at the siege of Chester. His instrumental music includes Great Consort for violin, bass viol, theorbo, and harp; The Royal Consort (a set of dance suites); and some fine fantasias, anthems, and psalms. His daring harmonies employ unusual dissonances. Lawes was a skilled contrapuntalist who after some difficulty mastered the idiom of the Baroque. He was also one of the principal masque composers, composing the music for James Shirley’s The Triumph of Peace (1634) and The Triumph of Beauty (c. 1644) and Sir William Davenant’s The Triumph of the Prince d’Amour (1636; with Henry Lawes) and Britannia Triumphans (1638).