The 2003 Dartmouth Big Green football team was an American football team that represented Dartmouth College during the 2003 NCAA Division I-AA football season. Dartmouth tied for second in the Ivy League. In their 12th season under head coach John Lyons, the Big Green compiled a 5–5 record and were outscored 261 to 211. Casey Cramer and Clayton Smith were the team captains. The Big Green's 4–3 conference record placed them in a four-way tie for second in the Ivy League standings. Despite its winning conference record, Dartmouth was outscored 168 to 161 by Ivy opponents.