most important English theatre proprietor and manager of the Elizabethan Age.

Henslowe had an interest in the suburban Newington Butts Theatre in 1594 and, later, in the Swan Theatre in the Paris Garden at the western end of the Bankside. The actor Edward Alleyn (Alleyn, Edward) had married Henslowe's stepdaughter, and Henslowe and he presented bearbaiting and bullbaiting (bearbaiting) in an old arena near the Swan. In 1613 Henslowe built a new theatre, the Hope (Hope Theatre), designed for plays as well as bearbaiting, on this site. The most sumptuous of Henslowe's theatres was the Fortune (Fortune Theatre), built just north of London for the Admiral's Men in 1600.

Henslowe's theatres gave the first productions of many important Elizabethan dramas; he was associated in one way or another with most of the famous playwrights for a quarter of a century, and his Admiral's Men were the chief rivals of the Chamberlain's Men (Lord Chamberlain's Men), Shakespeare's company. Henslowe was a shrewd, crotchety man of business who kept a tight hand on his theatrical companies, his players, and his playwrights. “Should these fellowes come out of my debt I should have no rule over them.” In the year before his death his players brought an indictment of “oppression” against him, but the outcome of the proceeding is not known.

Henslowe's famous Diary is one of the most important sources for the English theatrical history of the time. It is actually a manuscript book of miscellaneous accounts and memoranda, playhouse receipts, payments to playwrights, loans or advances to players, payments for materials, costumes, and so on. It was edited (1904–08) by Sir Walter Gregg and was supplemented by Henslowe Papers (1907), also edited by Gregg.