Kutcher plays a heartbroken internet billionaire, Walden Schmidt, who buys Harper's house after making a suicide attempt.
Last year's series opened with the funeral of Sheen's character, Charlie Harper, after he was apparently killed by a metro train in Paris.
All will return with small pay rises, US industry papers reported.
Sheen was sacked from the show last year after criticising its producers and months of reported drug use. About 28.7m tuned in to see Kutcher's debut.
US sitcom Two and a Half Men is to return for a tenth season, a year after Ashton Kutcher replaced Charlie Sheen.
He will also be seen later this year playing Steve Jobs in a film biopic of the late Apple Computers pioneer.
The deal follows protracted talks between Warner Brothers TV, Kutcher and his co-stars Jon Cryer and Angus T Jones.
The show's creator, Chuck Lorre, is also responsible for comedies such as Dharma and Greg and The Big Bang Theory.
The Hollywood Reporter says that, thanks to the show's success, Kutcher will receive "slightly more" than the $700,000 (£425,526) per episode he is thought to have made last year.
Instead, Kutcher was signed for a one-season contract. The actor explained: "The deal that we structured for the show was kind of a test deal: Can we get the show up? Can we get it going?"
It was the show's highest-ever audience and, although figures settled after the initial interest, the series was watched by an average of 15m viewers, a rise of 13%.
He admitted last year that he had considered cancelling Two and a Half Men following Sheen's departure.
His co-stars, who are paid less, will receive similar pay increases.
The show is broadcast by CBS in the States, and by Comedy Central in the UK
