On May 14, 2008, the Hamilton Tiger Cats announced the signing of Porter. He beat out Timmy Chang in the preseason to become the Ti-Cats third-string quarterback. He moved up to the second string on July 25 due to an injury to Casey Printers. He was moved up to the second string again for the September 12 game by new head coach Marcel Bellefeuille. Porter made his first start on September 27, 2008. Porter was sacked ten times by the BC Lions defense and went 14-of-27 for 144 yards with two interceptions in a 40-10 loss. His performance in his second start, 27-of-32 passing for 429 yards and five touchdowns including running himself for 42 yards on six carries, earned him the CFL's Offensive Player of the Week honours as well as the team's unexpected victory over the East's first place team, the Montreal Alouettes, and solidified his position as the number one quarterback on the Ti-Cats roster until the emergence of Kevin Glenn. For the 2010 and 2011 seasons, Porter was second string, backing up Glenn, in addition to coming in for short yardage situations. In 2011, Porter led the CFL in rushing touchdowns with nine. On January 15, 2013, the Tiger-Cats released Porter as per his request.