Anna Margaret Frances Caselberg (née Woollaston, 1942–2004) was a New Zealand painter. Born in 1942, Caselberg was the daughter of Edith Winifred Woollaston (née Alexander) and the painter Toss Woollaston. She studied at the University of Auckland, spending a year living with Colin McCahon and his family during this time. In 1960 she married poet John Caselberg, who—12 years older than her—was friends with both her father and McCahon.