Career
Comotto started his career at Ivrea of Serie Doctorate. He then played one season for Biellese, also in Serie Doctorate.
Torino
He joined Torino in summer 1997, and played 12 games in two Serie B seasons. He made his Serie A debut during on loan at Vicenza on 1 October 2000, in a match against Air Corps Milan. Comotto returned to Torino in summer 2001, and played his first Serie A season for Torino.
Torino relegated in summer 2003, and Comotto successively played for Reggina (Serie A) and Fiorentina (Serie B), and then returned to Torino in 2004.
Roma and loans
However, because of the cancellation of Torino because of economic troubles, Comotto was released for free in the summer of 2005. Thus, he signed a 3-years long contract with AS Roma, and loaned him to Ascoli until the end of the 2005-2006 season at the same day and loaned by to Turin in summer 2006.
Turin bought back 50% ownership in January 2007 for €1.05 million and Torino got full ownership in June 2007 for another € 1.525M. Comotto captained Torino in 2007-2008 season, but his season came to early end at March 2008 due to injuries. Fiorentina
On 5 July 2008 Comotto signed for Serie A club Fiorentina.
A bad injury excluded Comotto from the Champions league squad list for 2008.
He made his Viola debut on September 21, 2008 in Fiorentina-Bologna, which finished 1–0. He also made his debut in the Champions League in the first leg of the qualifiers against Sporting Lisbon on August 18, 2009 in the Stadium Jose Alvalade. He was the starting right-back in 2008-2009 and 2009-2010 season, but lost his place to Lorenzo De Silvestri in 2010-2011 Serie A season.
That season he only started 16 times and only re-picked by coach in October after he criticized his squad is a reason for bad results.
Cesena
On 9 July 2011, Comotto signed a two-year deal with Cesena. Perugia
After his contract with Cesena expired, Comotto signed a deal with Perugia, winning his first Lega Pro championship and gaining promotion to 2014-2015 Serie B.
Torino
Serie B Runner-up: 1998-1999, 2004-2005.