The 2009–10 Colorado Avalanche season was the franchise's 38th season, 31st in the National Hockey League (NHL) and 15th as the Colorado Avalanche.
Off-season
On June 3, 2009, the Avalanche began a complete overhaul of the coaching staff by firing head coach Tony Granato, along with assistants coaches Jacques Cloutier and Dave Barr, goaltending coach Jeff Hackett, assistant to the general manager Michel Goulet and video coordinator PJ DeLuca. Also on June 3, the Avalanche hired Greg Sherman as their new general manager, replacing Francois Giguere, who had been fired in April. On June 4, Joe Sacco was hired to be the new head coach. Before Sacco's hiring, an offer had been made to former Avalanche goaltender Patrick Roy to become head coach, which Roy declined.
Defenceman Adam Foote was named team captain following the retirement of long-time captain Joe Sakic.
Preseason
|- align="center" bgcolor="#ccffcc" | 1 || September 17 || Dallas Stars || 1 - 3 || Colorado Avalanche || || Anderson || 1-0-0 || |- align="center" bgcolor="#ffbbbb" | 2 || September 18 || Colorado Avalanche || 2 - 6 || St. Louis Blues || || Weiman || 1-1-0 || |- align="center" bgcolor="#ccffcc" | 3 || September 20 || St. Louis Blues || 1 - 2 || Colorado Avalanche || OT || Budaj || 2-1-0 || |- align="center" bgcolor="#ccffcc" | 4 || September 23 || Los Angeles Kings || 2 - 3 || Colorado Avalanche || || Anderson || 3-1-0 || |- align="center" bgcolor="#ffbbbb" | 5 || September 24 || Colorado Avalanche || 2 - 3 || Dallas Stars || || Budaj || 3-2-0 || |- align="center" bgcolor="#ffbbbb" | 6 || September 26(in Las Vegas) || Colorado Avalanche || 3 - 5 || Los Angeles Kings || || Anderson || 3-3-0 || |-
Regular season
On July 9, 2009, Avalanche captain Joe Sakic announced his retirement from the NHL after 20 seasons. The Avalanche retired Sakic's jersey #19 in a ceremony before the October 1, 2009 home opener of the 2009-10 season. On November 12, 2009, the Avalanche unveiled a new third jersey.
On February 10, 2010, Kyle Cumiskey scored just 9 seconds into the overtime period to give the Avalanche a 4-3 home win over the Atlanta Thrashers. It would prove to be the fastest overtime goal scored during the 2009-10 NHL regular season.
Divisional standings
Conference standings
Game log
|- align="center" bgcolor=#CCFFCC
| 1 || October 1 || San Jose Sharks || 2 – 5 || Colorado Avalanche || || Anderson || 18,007 || 1–0–0 || 2 || |- align="center" bgcolor=#CCFFCC | 2 || October 3 || Vancouver Canucks || 0 – 3 || Colorado Avalanche || || Anderson || 13,416 || 2–0–0 || 4 || |- align="center" bgcolor=#FFBBBB | 3 || October 8 || Colorado Avalanche || 2 - 3 || Nashville Predators || || Anderson || 14,797 || 2-1-0 || 4 || |- align="center" bgcolor=white | 4 || October 10 || Colorado Avalanche || 3 - 4 || Chicago Blackhawks || SO || Anderson || 20,655 || 2-1-1 || 5 || |- align="center" bgcolor=#CCFFCC | 5 || October 12 || Colorado Avalanche || 4 - 3 || Boston Bruins || || Anderson || 16,393 || 3-1-1 || 7 || |- align="center" bgcolor=#CCFFCC | 6 || October 13 || Colorado Avalanche || 4 - 1 || Toronto Maple Leafs || || Anderson || 19,148 || 4-1-1 || 9 || |- align="center" bgcolor=#CCFFCC | 7 || October 15 || Colorado Avalanche || 3 - 2 || Montreal Canadiens || || Anderson || 21,273 || 5-1-1 || 11 || |- align="center" bgcolor=#CCFFCC | 8 || October 17 || Colorado Avalanche || 4 - 3 || Detroit Red Wings || SO || Anderson || 19,763 || 6-1-1 || 13 || |- align="center" bgcolor=white | 9 || October 21 || Colorado Avalanche || 2 - 3 || Minnesota Wild || SO || Anderson || 18,175 || 6-1-2 || 14 || |- align="center" bgcolor=#CCFFCC | 10 || October 23 || Carolina Hurricanes || 4 - 5 || Colorado Avalanche || || Anderson || 13,673 || 7-1-2 || 16 || |- align="center" bgcolor=#CCFFCC | 11 || October 24 || Detroit Red Wings || 1 - 3 || Colorado Avalanche || ||Anderson || 17,690 || 8-1-2 || 18 || |- align="center" bgcolor=#CCFFCC | 12 || October 27 || Colorado Avalanche || 3 - 0 || Edmonton Oilers || || Anderson || 16,839 || 9-1-2 || 20 || |- align="center" bgcolor=#CCFFCC | 13 || October 28 || Colorado Avalanche || 3 - 2 || Calgary Flames || || Anderson || 19,289 || 10-1-2 || 22 || |- align="center" bgcolor=#FFBBBB | 14 || October 30 || Colorado Avalanche || 1 - 3 || San Jose Sharks || || Anderson || 17,562 || 10-2-2 || 22 || |-