The 2003 Portland Timbers season was the 3rd season for the Portland Timbers—the 3rd incarnation of a club to bear the Timbers name—of the now-defunct A-League, the second-tier league of the United States and Canada at the time.

Division Final round of playoffs Source: [1] Pld = Matches played; Pts = Points; W = Matches won; T = Matches tied; L = Matches lost; GF = Goals for; GA = Goals against; GD = Goal difference

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Players may hold more than one non-FIFA nationality.

A-League All-League Second Team[4] A-League Player of the Week[5] A-League Team of the Week All players contracted to the club during the season included.