Volchenkov, 25, recorded career highs in assists (18), points (19) and penalty minutes (67) this season. The Moscow native also led the league in blocked shots (273), was fifth in plus-minus (plus-37) and was 12th in hits (205).
"Anton has been one of our top defencemen all season," GM John Muckler said in a statement. "We're pleased to have secured him for the next three years, two of which were restricted and the third season when Anton would have been an unrestricted free agent."
Volchenkov has nine goals, 46 assists and 168 penalty minutes in 229 career games. He has also added one goal, five assists and 18 penalty minutes in 31 career playoff games.
Volchenkov will get $2.1 million next season, $2.2 million in 2008-09 and $3.2 million in 2009-10.
Drafted by the Senators in the first round (21st overall) in the 2000 NHL entry draft, Volchenkov has spent his entire career in Ottawa.