Orr attended Galveston Community College in Galveston, Texas. He was a draft pick of the Texas Rangers in 1998 spending one year there before signing with the Atlanta Braves July 3, 1999. He was part of Team Canada who finished in fourth place at the 2004 Summer Olympics. His excellent fielding and speed combine with a genuine humility and positive attitude that earned him the 2004 Bill Lucas Award (Atlanta Braves Minor Leaguer Best Exemplifying Sportsmanship and Character) and make him a valuable utility player for the Braves.
Orr made his Major League debut for the Braves on April 5, 2005. He has proven to be a versatile player, playing second base, third base, and various outfield positions during the 2005 season. Orr was also a member of the 2004 Canadian Olympic team and played for Canada in the 2006 World Baseball Classic.
Orr stands 6'1" and weighs 185 lbs. He is not related to hockey legend Bobby Orr, although Pete does wear the same number as Bobby, #4. Pete was given the number by the Braves, but prefers it because his friends in Canada always wanted him to wear it. (Sports Illustrated, 2006)