Hamilton attended Middlebury College from 2005 to 2009, during which time he competed for its ski team, individually earning several All-American NCAA Championship results.

He paced all Americans in the field in the 1.5 kilometer sprint by advancing to the medal rounds and finishing 29th of 96 competitors.

In the relay, Hamilton pulled away from the Estonian skier in the anchor leg to secure a 13th-place finish.

On December 31, 2013, Hamilton won Stage 3 of the 2013–14 FIS Tour de Ski, a 1.5 kilometer freestyle sprint.

In doing so, he became the first American male skier to win a World Cup race since Bill Koch won the Sarajevo 30 km in February 1983.