The comedian's self-titled series was a cult hit in the '90s, taking Hill's irreverent radio series Fruit Corner onto the small screen.
Harry Hill, which ran for three series, was a mixture of stand-up, sketches, songs and regular characters played by guests such as Al Murray and Burt Kwouk.
Famous skits on the show included Stouffer the Cat, the Badger Parade and Kwouk playing a chicken catcher.
Channel 4 has revealed that Harry Hill: The Reunion will "be a one-off show hosted by Harry looking back at the seminal series". It will feature Harry "seeking out the cast and asking, 'Where are they now?'"
The special is part of Channel 4's Funny Fortnight season, a two-week run of new shows, stand-up and familiar faces.
Shane Allen, Channel 4 Head of Comedy, said: "Channel 4 has been at the forefront of British comedy from day one. We've launched so many careers by backing new talent and have never been afraid to get in trouble all for the comedy cause.
"Channel 4's Funny Fortnight is a chance to celebrate our achievements with a raft of new shows featuring many of the biggest names in British comedy."
Watch a clip of Harry Hill's classic Channel 4 show below: