Born in
Timaru on 3 March 1935, Elworthy was the son of June Mary Elworthy (née Batchelor) and Harold Herbert Elworthy, and the grandson of
Edward Elworthy. He had two brothers,
Jonathan Elworthy, a New Zealand politician, and
David Elworthy, a publisher. Peter Elworthy was educated at
Christ's College from 1949 to 1953, and then completed a diploma at
Canterbury Agricultural College in 1955. In 1960, Elworthy married Fiona Elizabeth McHardy, and the couple went on to have four children, including economist and social scientist
Charles Elworthy. ==Career==