Colby Joseph Armstrong (born on November 23, 1982 in Lloydminster, Saskatchewan) is a Canadian professional ice hockey player and alternate captain currently playing for the Atlanta Thrashers.

Armstrong grew up in Saskatoon, Saskatchewan in the city's northeastern neighborhood of Erindale, where he continues to live in the off-season. He played youth hockey with the Saskatoon Red Wings and the Saskatoon Blazers. Additionally, as a child he was a figure-skater. He, along with Los Angeles Kings forward Jarret Stoll attended St. Joseph High School in Saskatoon.

Armstrong was drafted by the Pittsburgh Penguins in the first round of the 2001 NHL Entry Draft as the 21st pick overall.