Crowther has been appointed at another NHS trust which is yet to be named.
'It has been a pleasure to be a part of the leadership team here at UHDB,' Crowther said.
'As a trust we have seen a lot of change over the last few years and there have been a lot of challenges to overcome, but I have seen our teams across the organisation show real resilience and a determination to do always do the best we can for our patients.
'I look forward to seeing what lies ahead for UHDB and wish the trust every success for its future.'
Crowther joined the trust in September 2020 as executive director of finance and performance, before also becoming deputy chief executive in 2021.
He formerly held roles at board level across a number of NHS organisations, and throughout his career has worked across different sectors and health communities within the NHS.
Chief executive Stephen Posey said: 'Simon is a leader who has truly lived our values.
'His leadership has steered the trust through a challenging financial backdrop, and he has been a driving force in taking forward our sustainability agenda and our new trust strategy, which sets our roadmap for the future.
'On behalf of UHDB I want to thank Simon for his calm, professional leadership, and wish him every success in his next steps.'