Brentnall is a surname. Notable people with the surname include:
Bev Brentnall (born 1936), New Zealand cricketer Frederick Thomas Brentnall (1834–1925), English-born Australian Wesleyan preacher and politician Greg Brentnall (born 1956), Australian rugby league footballer Lyndon Brentnall, security company owner, RMS Protective Services Sandra Brentnall (born 1962), Australian soccer player Thomas Brentnall (1846–1937), English-born Australian chartered accountant