The England defender is out of contract at the end of the season and, with the player seemingly intent on leaving, the Trotters are looking to cash in on one of their most prized players when the transfer window opens next month.
Chelsea boss Andre Villas-Boas made his interest in the 26-year-old public earlier this week with Cahill set to offer, at the very least, much-needed depth at centre-half after the Blues accepted a transfer request from Alex earlier this month.
And Villas-Boas' interest has apparently moved a step forward in the past few days after Bolton revealed that negotiations had begun.
"Regarding Gary Cahill, there has been dialogue between ourselves and Chelsea. He is a top player and is fully focused on Bolton," a brief statement on their Twitter page read.
Manager Owen Coyle had earlier confirmed that talks with another Premier League club had begun in his press conference this morning.
While the Scot said there was not yet any concrete deal, he admitted Cahill's departure could pave the way for the addition of two or three new names as he looks to drag his side out of the relegation zone.
"There's nothing signed and sealed at the moment but it's fair to say there has been dialogue here and there," Coyle said.
"I think it's fair to say there's interest in Gary and there will be and that doesn't surprise me.
"I know that Andre is an admirer of Gary because he's a terrific player so if there's business to be done it will be done in the right manner for the football club and for Gary.
"I've got to be upfront and tell you as I always do but that's the situation, and Gary knows as well that there are two huge games before January 1st before anything could happen.
"I've said from day one, Gary Cahill could play for anybody.
"I think he has those qualities."
Despite the interest in Cahill - Tottenham are also reportedly keen on the player - Coyle is confident the former Aston Villa defender will remain committed to his side's cause until any deal is brokered.
"What January will bring it will bring, but I think it's fair to say there is serious interest in Gary," he added.
"But - and it's a big but -we have two huge games before January 1, and because of the lad Gary is, his focus will be doing to best for his team-mates who he has stood shoulder to shoulder with for years at Bolton Wanderers and trying to help them and the get points in these two games.
"Whatever January brings, so be it."
Cahill joined Bolton in a £5million move from Villa in January 2008 and earned his place in the England squad this season.
Villas-Boas spoke of his interest in the defender earlier this week as a potential solution to the issue raised when Alex handed in a transfer request.
Chelsea have also found themselves short-handed at centre-half following injuries to David Luiz and Branislav Ivanovic, who limped out of Thursday night's 1-1 draw against Tottenham with a hamstring complaint.
"We are aware of Gary's contractual situation. He's an interesting player for the club," Villas-Boas said.
"We haven't decided what we are going to do with the Alex situation. We have to make the wisest decision, be it Alex, be it Cahill."
Looking to the rest of his squad, Coyle expects to bring in a few new faces to provide a boost to the club for the remainder of the season.
He said: "We know as a football club given the injuries and suspensions we've had that we certainly need two or three [new players] to freshen us up and give us a new impetus for the second half of the season, so there's business to be done.
"Come January 1 we'll see what happens but I think it's fair to say it will be an interesting month."