Gerald Gary Mercurio OBE (born September 1966) is a British television writer, producer, director and novelist.

A former hospital doctor[5] and Royal Air Force officer,[6] Mercurio has been ranked among UK television's leading writers.

[10] Mercurio's works for television include the series Line of Duty, Bodyguard, Bodies (based on his 2002 novel), The Grimleys, and Cardiac Arrest.

Mercurio's writing debut, Cardiac Arrest (1994–96), caused controversy due to its realistic depiction of hospital life.

[42] Mercurio's third medical drama series, Critical, ran for 13 episodes on Sky1 from 24 February 2015 to predominantly positive reviews,[43][44][45][46] but was cancelled on 15 July 2015 after one season.

[47] Mercurio created and wrote Bodyguard, serving as showrunner on the six-part series starring Richard Madden and Keeley Hawes.

[51] In 2023, HTM created the six-part drama Payback, starring Morven Christie opposite Peter Mullan, which aired on ITV and internationally.

[53] Mercurio was appointed Officer of the Order of the British Empire (OBE) in the 2021 New Year Honours for services to television drama.