Fisher had five goals and five assists in 20 playoff games last season for the Senators, who reached the Stanley Cup finals for the first time. His 73 playoff hits ranked second overall.
A finalist for the Selke Award in 2005-06 as one of the NHL's top defensive forwards, the 27-year-old Fisher would have been eligible to become an unrestricted free agent following the 2007-08 season. He will earn $1.5 million this season, $6 million in the 2008-09 season, $4 million each of the next three seasons, and $3 million in 2012-13.
He tied his career high with 22 goals in 68 regular-season games in 2006-07, adding 26 assists for 48 points, both personal bests.
Fisher has 92 goals and 100 assists in 384 regular-season games in seven seasons with the Senators, who selected him in the second round of the 1998 draft.