On 3 December 2018, Ricketts was appointed manager of Shrewsbury on a 2-year contract, leaving a Wrexham side fourth in the table. Two days later in his first match, Shrewsbury won 2–1 against Walsall to reach the third round of the EFL Trophy; he was the first manager to win on his Shrewsbury debut since Graham Turner in 2010. He brought in eight players in the January 2019 transfer window including Tyrese Campbell, Ro-Shaun Williams and Scott Golbourne. In early 2019, Ricketts lead the club to the fourth round of the FA Cup. The club's cup run ended at the hands of rivals, and one of Ricketts' former clubs, Wolverhampton Wanderers. Town were 2–0 up in the original tie at New Meadow with just under 20 minutes to play, but late goals from Raúl Jiménez and Matt Doherty took the tie to a replay at Molineux. Ricketts' Shrewsbury side went 1–2 up in the replay, only to eventually lose 3–2. A 1–1 draw away at Coventry City on 28 April mathematically secured League One survival for Ricketts and the club.