Leighton, who would have been an unrestricted free agent at noon ET Thursday, will earn $1.5 million next season and $1.6 million in 2011-12.
He earned $600,000 this past season while leading the Flyers to the Stanley Cup finals, where they lost in six games to the Chicago Blackhawks.
He went 8-3 with a 2.56 goals-against average in 14 playoffs games and set a team playoff record with three shutouts as Philadelphia won its first Eastern Conference championship since 1997.
In 27 appearances in the regular season, Leighton was 16-5-2 with a 2.48 GAA.
The Flyers acquired him on waivers from the Carolina Hurricanes in December. Leighton missed the final 13 games of the regular season and the first nine games of the playoffs because of an ankle injury.
Pierre LeBrun covers the NHL for ESPN.com. Information from The Associated Press was used in this report.