Alviro Nathan Petersen (born 25 November 1980 in Port Elizabeth) is a South African cricketer who plays his domestic cricket for the Highveld Lions. He has represented his country at international level in One Day International cricket as a specialist batsman. On the 14th of February 2010, he became the third South African after Andrew Hudson and Jacobus Rudolph to score a century on Test debut. His nickname is "the lock".
On 16th November 2010 it was announced that Petersen had signed for Glamorgan County Cricket Club for the 2011 English county season and had also been appointed as county captain replacing Jamie Dalrymple.