Sir Gervase Helwys (1 September 1561 – 20 November 1615), also known as Jervis Yelwys, was a Lieutenant of the Tower of London found guilty of complicity in the murder of Sir Thomas Overbury and hanged in 1615. The scandal provoked much public and literary conjecture and irreparably tarnished King James I's court with an image of corruption and depravity. There are variations in the spelling of Helwys: Helwis, Helwiss, Helewyse, Helwysse, Yelwys, Ellowis, Elwys, Elwis, Elvis, Elwes, and Elwaies.