Coming off his lowest points total since his rookie season (excluding his shortened 31-game season in 2003–04), TSN reported that Heatley had filed a request for a trade on June 9, 2009, despite being only one year into a six-year contract extension signed in 2007. Heatley had reportedly become unhappy with his role with the Senators under new head coach Cory Clouston. Despite his declining offensive numbers, Heatley felt that his decreased ice time and his move from the first power-play line to the second power-play line were unfair to him. Prior to the trade request, these concerns had been brought to the attention of management during the Senators' year-end meetings.
Trading Heatley was a challenge due to his large contract, a contract that was to pay him approximately $7.6 million for the upcoming 2009–10 season, and few other NHL teams possessed the available salary cap space to accommodate it. Further complicating matters was the partial no-trade clause in Heatley's contract which limited the number of teams Ottawa could negotiate a potential deal with. A trade was worked out to send Heatley to the Edmonton Oilers in exchange for Andrew Cogliano, Dustin Penner and Ladislav Šmíd on June 30, 2009, but Heatley again surprised the hockey world when he refused to waive the no-trade clause which would have finalized the deal, further angering fans in both Ottawa and Edmonton. NHL Deputy Commissioner Bill Daly suggested that the Senators may have grounds to file a grievance, as Heatley's contract stipulated the team pay a bonus (due July 1, 2009) of US$4 million. The Edmonton trade would have spared the Senators that expense.
As Ottawa GM Murray began again to try to accommodate the trade demand, Heatley was still a member of the Senators as the team opened training camp on September 12, 2009. Heatley had little choice but to report for training camp, and the atmosphere between him and his Senators' teammates was described as "awkward", "tense", and "untenable". Team captain Daniel Alfredsson admitted days earlier that a scenario in which Heatley showed up in Ottawa as an unhappy camper would create a massive media headache for the rest of the team. "If he comes back there's going to be a lot of focus and attention," Alfredsson said at the time, adding "If somebody hits him in practice or something occurs, everything is going to get blown out proportion." Heatley himself snuck back into Scotiabank Place, avoiding the cameras and throng of media awaiting some clarification regarding his desire to leave Ottawa. "When I looked (Heatley) in the eye, I knew the minute he walked out the door that I had to trade him," GM Bryan Murray said a short time later. "I didn’t think there was any chance. I just felt that we had to move him."
On September 12, 2009, Heatley was traded to the San Jose Sharks, along with a fifth-round pick in 2010, for Milan Michálek, Jonathan Cheechoo and a second-round pick in 2010. Heatley made $8 million that year.
Heatley has been voted into the NHL All-Star Game five times, and played in four of them, most recently in 2009. His first appearance in the All-Star Game was in 2003, where he scored four goals, tying a single-game All-Star record (held by four other players, including Wayne Gretzky). The game went to a shootout where Heatley scored the only goal for the Eastern Conference in a 6–5 loss. The shootout goal did not, however, count towards his regulation total of four, leaving him tied for the record. Heatley also added an assist for a game-high five points and was named the All-Star Game MVP. In response to Heatley's impressive performance in just his second NHL season, Eastern Conference teammate Jeremy Roenick commented, "Twenty-two years old? You're not supposed to be able to pull moves like that at 22. My goodness."
In the summer of 2009, Heatley was invited to Team Canada's Olympic tryout camp in Calgary, where he was booed on the ice by fans. On December 30, 2009, Heatley was selected to play for Team Canada at the 2010 Winter Olympics. Heatley helped lead Team Canada to an 8–0 win in the first game of the 2010 Olympic tournament by scoring two goals. On February 28, 2010, the team defeated the United States to win Canada's eighth gold medal in Olympic men's hockey.