Kemba Walker is heading to the Boston Celtics.

The long-time Charlotte Hornets guard has committed to signing a four-year, $141million contract with the Celtics, his agent Jeff Schwartz told ESPN.

Even though Walker insisted his top choice was to stay with the team that selected him ninth overall in the 2011 draft, he could not pass up the Celtics' offer after a tough couple of years that saw the Hornets miss the playoffs in three consecutive seasons.

"I think that's what it was, moving onto the next thing, just moving on to a whole new chapter in my basketball career," Walker told SportsCenter.

"I gave that city [Charlotte], gave that organisation every single thing I can possibly give them.

"Now, it's about competing at the highest level, which we all know Boston is doing that year in, year out and I want to be a part of something really special as far as being able to compete at the highest level, getting myself the best opportunity to make a run in the playoffs."

Walker averaged a career-high 25.6 points, along with 5.9 assists, for Charlotte last season. He shot 43.4 per cent from the field and 35.6 per cent from three-point range.

The Hornets will attempt to replace Walker with Terry Rozier, who they reportedly acquired in a sign-and-trade with Boston on Sunday.