He is thought to have been the son of John Lacy, musician (d.1621), and had a sister, Elizabeth (born c.1616), who later married Roger Parker.
After the English Interregnum period, once Charles II returned to the throne and the London theatres re-opened, Lacy became an actor with the newly formed King's Company.
[3] Lacy quickly evolved into a popular comedian; Samuel Pepys admired and enjoyed his work, as he recorded in his Diary.
[4] Lacy was also known for the role of Galliard in the Duke of Newcastle's play The Variety, and Scruple in John Wilson's The Cheats.
He played roles in Ben Jonson's comedies: Ananias in The Alchemist, Captain Otter in Epicene, and Sir Politic Would-Be in Volpone.
Lacy lived with Mary Dickons, widow, from 1639 to 1649 – initially as a lodger, but subsequently as man and wife, although there is no convincing evidence that they ever in fact married.
Around 1656, under the pseudonym of "Sir John Burlacy", he allegedly began to court a wealthy woman named Penelope Long.
[7] According to Sir George Etheredge, Lacy was the lover of Nell Gwyn along with the King's Company star Charles Hart.