Champneys was born in Whitechapel, the son of the Very Rev William Champneys (rector of St Mary Whitechapel then Dean of Lichfield) and his wife Mary Ann Storr. He was educated at Brasenose College, Oxford. He rowed bow in the Oxford crew in the 1861 Boat Race. Also in 1861 he partnered Walter Bradford Woodgate to win Silver Goblets at Henley Royal Regatta. The pair repeated their success in 1862.
Champneys died at Haslingden at the age of 52.
Champneys married Frances Sophia Feilden in Kensington on 1879. His brother Basil Champneys was an architect and author and his brother Sir Francis Champneys, 1st Baronet a doctor. Francis Champneys was bow in Woodgate's infamous coxed four in 1868 when the cox jumped overboard.
- Henley Royal Regatta Results of Final Races 1839-1939
- British Census 1881 RG11 4138/13 p 20
- Dalrymple-Champneys, W (1963). "SIR FRANCIS CHAMPNEYS" (PDF). Proc R Soc Med. 56: 26–7. PMC . PMID 14044494.