He started his career at Caltex in 1996 and became CFO since 2001.
In his time as CFO, Mr Hepworth has been responsible for leading the financial discipline that has been fundamental to the transformation of Caltex.
Caltex is in the process of recruiting its new CFO and will make that announcement in due course.
To ensure continuity through the transition phase, Mr Hepworth will remain in his role until mid-2019 to ensure an appropriate handover with his successor.
Shares in Caltex Australia (ASX:CTX) are trading 1.09 per cent higher to $29.72.