Steyn is a Dutch surname.

The most common South African progenitor was Douwe Gerbrand Steyn who arrived in South Africa in c. 1672 as a stonemason and married Maria Lozee in 1685. Notable people with the surname include:

• Andrie Steyn, South African cricketer
• Carole Steyn (born 1938), British abstract painter
• Christo Steyn (born 1961), South African tennis player
• Dale Steyn (born 1983), South African cricketer
• Douw Steyn (born 1952), South African billionaire businessman
• Esme Steyn (born 1953), South African lawn bowls player
• François Steyn (born 1987), South African rugby player
• Gary Steyn (born 1961), Zimbabwean cricketer
• Hermanus Steyn (1743–1804), President of Republic of Swellendam
• Johan Steyn, Baron Steyn (1932–2017), South African jurist
• Lucas Cornelius Steyn (1903–1976), South African politician
• Mark Steyn (born 1959), Canadian journalist
• Martinus Theunis Steyn (1857–1916), South African lawyer, politician, and statesman
• Morné Steyn (born 1984), South African rugby player
• Pieter Steyn (1706–1772), Dutch politician
• Richard Steyn (born 1944), South African newspaper editor, historian and cricketer
• Rudi Steyn (born 1967), South African cricketer
• Santjie Steyn (born 1972), South African lawn bowls player
• Stephen Steyn (1889–1917), South African rugby union player and soldier
• Stephen Steyn (cricketer) (1905–1993), South African cricketer
• Trish Steyn (born 1952), South African lawn bowls player