The 29-year-old has put pen to paper on a two-year extension to his previous deal, which was due to expire next summer.
Doidge, who has been out of action since August with an Achilles injury, has been a keenly felt miss for the Easter Road side this season.
He is now back in full training and could be involved as early as Sunday’s Premier Sports Cup semi-final encounter with Rangers at Hampden Park.
Speaking to the club after his extension was confirmed, Doidge expressed his joy at committing his future to what he called “a massive football club”.
“I’m delighted,” he said. “As soon as they approached me about signing an extension it was a really easy decision to make.
“This is the club I want to play for, and I’ve enjoyed my time here more than anywhere else.
“This is a massive football club, with a really big fanbase, and the coaching staff have been brilliant with me. I’m really enjoying my football and I hope I can help the team to be successful.”
Doidge joins the likes of Paul Hanlon, Lewis Stevenson and Martin Boyle in agreeing new contracts this season and manager Jack Ross stated his pleasure the club were able to tie down another one of his first-team stars.
“It was important for us to agree a new contract with Christian because we want to keep players like him at the club,” he said.
“Strikers are always going to be judged on their goal return, Christian's record in this regard has been really good. Furthermore, his all-round contribution is of great value to the team.
“Alongside his ability, he’s a good person, a strong character, and he wants to help the team move forward.”
The Welshman has scored 34 goals in 91 appearances in all competitions after joining the club from Forest Green Rovers in 2019 for a fee reported to be in the region of £350,000.
His last appearance came in a 3-0 victory over Ross County on August 8 where he netted the third and final goal before suffering the Achilles injury in training the following week.