During his career as a player, he had spells at Aston Villa, Plymouth Argyle, Sunderland, Ipswich Town and Derby County and Barnsley.

He signed for Football League Two side Plymouth Argyle on 30 July 2011 on a free transfer after being released by Ipswich and impressing on trial.

[19] On 26 January 2017, it was confirmed that Hourihane had left Barnsley to sign for Championship rivals Aston Villa for an undisclosed fee.

[22] Hourihane signed a new three-year deal in the summer of 2019 as a reward for helping the side win promotion to the Premier League.

[32][31] Ahead of the 2023–24 season, Hourihane was named the captain of Derby County on 3 August 2023, after winning the vote from the first-team squad.

[33] There were mixed fortunes for Hourihane at the start of his first season as captain with a low-light being Derby's 1–0 loss at Shrewsbury Town on 21 October 2023, where he scored the decisive own goal from defending a cross.

[34] At the end of the match, Houirhane went over to the angry visiting fans saying he was "trying his best",[35] he also stated frustration in the dressing room over poor performances.

[39] For the final six games of the season, Hourihane lost his place in the starting 11 as Nathaniel Mendez-Laing became on the pitch captain for the team during the promotion run-in.

[45] On 28 March 2017, Hourihane made his senior international debut, starting in a 1–0 friendly defeat against Iceland at the Aviva Stadium.

A portion of the Republic of Ireland supporters threw tennis balls on the pitch during the 33rd minute to express their discontent at Delaney remaining part of the FAI hierarchy.

In June 2023, he announced that he would be joining the Aston Villa Academy in September as a coach for the Under-16s team, alongside playing for Derby.