On 19 October 2017, Brennan was announced as the head coach of the Gold Coast Titans. His first senior head coaching role, Brennan became just the third head coach in the club's history. On 14 July 2019, Brennan was terminated from his position as Gold Coast head coach after the club were sitting last on the table after only winning 4 out of 17 matches. Brennan had only managed 12 wins from a possible 40 matches in his tenure at the Gold Coast club.
