Peter O'Connor was born in Wicklow, around 1872, but spent most of his life in Waterford. He was a world athlete and commenced his athletic career in 1898. His first All-Ireland Championship competition was in 1899. He broke the world record for the long jump at this competition, and also broke records in the 200 yards race and the Hop, Skip and Jump (48 feet). In 1901 he set the world record in the long jump of 24 feet, 11.75 inches, in Dublin. This remained an international record for 25 years and an Irish record for 89 years.

He was British long jump champion from 1901 to 1906. His best athletic years were between 1900 and 1904. He won the Gold Medal in the hop, skip and jump, and the Silver Medal in the long jump at the Olympics of 1906 (tenth anniversary games at Athens). He was 34 years of age at this stage, which made his achievements all the more remarkable. At that time Irish athletes competed under the British flag. O'Connor refused to wear British colours at the medal ceremony and insisted on waving a green flag to indicate his nationality.