On 20 February 2012, just five days after Lee Clark was dismissed as manager, Grayson became the new manager of League One club Huddersfield Town on a -year deal. His first game in charge of the Terriers was in their 2–0 home victory over Exeter City when both defender Jamie McCombe and leading striker Jordan Rhodes scoring he also introduced Icelandic midfielder Joey Guðjónsson to the squad for the first time all season. While remaining unbeaten, his next five games in charge proved to be mostly unspectacular, resulting in four draws against Stevenage, Bury, Rochdale and Colchester United also defeating Hartlepool United in a 1–0 home victory. The early pattern of these results remained similar to those of the previous manager, Lee Clark who managed a number of draws, which were held responsible for the Terrier's inability to cement a place in the automatic promotion spots. With 10 games remaining Town occupied 4th position in League One, contrary to the chairman Dean Hoyle's brief urging the club to reach one of the top two positions. On 26 May 2012, Grayson led Huddersfield to play-off victory over Sheffield United, gaining promotion to the Championship.