Matthew Wright has quit his role as host of long-running show The Wright Stuff.
Despite being named after the star, Channel 5 said the programme will continue with another presenter.
Wright said it was time to try new projects.
The 52-year-old, who has presented the weekday show since its launch in September 2000, said: “After almost 18 glorious years on Channel 5 and with the show flying high in the ratings, I feel it’s time to depart and try my hand at something new.”
Channel 5 said it was too early to say what would happen to the name of the morning show.
Director of programmes Ben Frow said: “We would like to thank Matthew for his passion, hard work and enthusiasm over the last 18 years and for making the show what it is today.
“He will be sorely missed and we wish him all the very best for the future.”
A replacement host is yet to be announced.
But stand-ins for Wright have included Richard Madeley and Anne Diamond.