Pieter Willem Adriaan Mulder, known as Wiaan Mulder, is a South African first-class cricketer. He made his ODI debut for South Africa in October 2017 and his Test debut in March 2019. In domestic cricket, Mulder plays for Imperial Lions and Gauteng. Mulder was a member of the South African team which won the 2025 ICC World Test Championship final, the second ICC title the country has won till date.