William Allen (died 1647) was a prominent English actor in the Caroline era. He belonged to both of the most important theatre companies of his generation, Queen Henrietta's Men and the King's Men.
Allen was a member of the Queen Henrietta's company through the main phase of its existence, from 1625 to 1636. Six cast lists for five plays survive for the company; Allen is one of only two men (the other being Michael Bowyer) who is included in all six lists. Allen played major roles:
The Queen Henrietta's company was disrupted and fractured by the long theatre closure from May 1636 to October 1637, due to a severe outbreak of bubonic plague. Allen was one of several members of the troupe who disappear from the surviving records in the later 1630s; he may have been among a quartet of Queen's actors who travelled to Dublin with James Shirley to work at the Werburgh Street Theatre there.