William Ecclestone or Egglestone (fl. 1610 – 1623) was an actor in English Renaissance theatre, a member of Shakespeare's company the King's Men.
Nothing is known with certainty about Ecclestone's early life. There was an Eccleston living in Southwark in 1583, and a person of the same name lived in Swan Alley, near the Swan Theatre, in 1601; this may have been one (or two) of the actor's family. (No personal name is given in the records in either case.) A "William Eglestone" was married to an Ann Jacob on 20 February 1603 at St. Saviour's in Southwark; this might (or might not) have been the actor.
The man who definitely was the actor was with the King's Men in 1610 and 1611; he was part of the cast of their productions of Jonson's The Alchemist (1610) and Catiline (1611). In the latter year he left the King's Men for the Lady Elizabeth's Men; he became a sharer in that company and signed a bond with impresario Philip Henslowe on 29 August 1611, along with other actors who included Joseph Taylor and John Rice, two King's Men of the future. Ecclestone acted with that company in their production of The Honest Man's Fortune, most likely in 1613. Yet Ecclestone returned to the King's Men later in 1613, and was in their production of Fletcher's Bonduca that was performed around that time. He became a sharer in the King's Men sometime between 1614 and 1619.