The former Linfield boss led the Sky Blues to three Irish Cup finals and three BetMcLean Cup deciders – including a 2-0 triumph over Carrick Rangers in the 2016/17 finale – and helped them secure European football on two occasions.
A titan of the local game, Jeffrey finished his Ballymena reign with a win percentage of 47%, coming out on the right side in 163 of his 346 games at the Showgrounds.
Here are all the best photos from his Ballymena reign, from cup victories to European adventures.
5. Passports at the ready
David Jeffrey celebrates after Ballymena United defeated Glenavon 2-1 in the 2016/17 Europa League play-off. The Sky Blues finished fourth in the table and goals from Cathair Friel and Kevin Braniff booked their spot in Europe. Photo: Presseye / Stephen Hamilton
6. Winning feeling
David Jeffrey is covered in champagne after Ballymena United secured their European spot Photo: Presseye / Stephen Hamilton
7. European clash
David Jeffrey watches on as Ballymena United play Norwegian outfit Odd in Europa League qualifying at Seaview Photo: Philip Magowan / PressEye
8. Fall just short of retaining Irish League Cup
David Jeffrey celebrates with Kyle Owens after Ballymena United equalised in the 2017/18 Irish League Cup final against Dungannon Swifts. They would fall to a 3-1 defeat as the Sky Blues missed out on the chance to retain their cup crown. Photo: Stephen Hamilton/Inpho