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.
9. County Antrim Shield final defeat to Crusaders
Crusaders defeated Ballymena United 4-2 in the 2017/18 County Antrim Shield final at the Ballymena Showgrounds. Howard Beverland is pictured opening the scoring after eight minutes. Photo: Arthur Allison/Pacemaker Press
10. Back in Europe
After finishing second in the Danske Bank Premiership during the 2018/19 season, Ballymena United were back in Europe. They progressed to the next round for the first time in the club's history following a 2-0 aggregate triumph over NSÍ Runavík (Faroe Islands) Photo: ©INPHO/PressEye.com/Jonathan Porter
11. Malmo put Ballymena United out of Europa League
David Jeffrey's men suffered a 4-0 home defeat to Malmo in the next Europa League qualifying round and were knocked out 11-0 on aggregate by the Swedish side. Photo: Colm Lenaghan/Pacemaker Press
12. Third consecutive Irish League Cup final ends in defeat
Ballymena United reached a third consecutive Irish League Cup final under David Jeffrey but it ended in a 1-0 defeat to Linfield. Photo: ©INPHO/Jonathan Porter