Lavan, John Thomas (‘Sean’) (1898–1973), athlete, footballer, and medical doctor, was born 22 September 1898 in Kiltimagh, Co. Mayo, eldest of four children of Michael Lavan, landholder, and Bridget Lavan (née O'Brien). Educated locally at Ballyglass national school, he won a king's scholarship to De La Salle College, Waterford, where he trained as a national schoolteacher, and was appointed (1919) to his first post in Cloongullane national school, near Swinford, Co. Mayo. His sporting career began at school, where he represented De La Salle at Gaelic football and boxing. A member of the Mayo senior Gaelic football team (1918–24), winning two Connacht senior championships, he is credited with introducing the toe-to-hand solo run into Gaelic football in the early 1920s; he used the skill to score a point that was disallowed, but the toe-to-hand was subsequently legalised. He was also an accomplished handball player, which earned him the nickname ‘Baller’ Lavan.
In 1923 he entered UCD to study medicine, qualifying in 1929, when he was awarded the O'Ferrall medal for surgery by St Vincent's hospital. Following a period of post-graduate study in the USA, he returned to Ireland in 1931 to work as a surgeon at Temple St. children's hospital in Dublin, a post he held till 1972. He also opened a general practice in Terenure, lectured in anatomy at UCD, and held the post of doctor to the Garda Síochána. While at UCD he became a prominent athlete: representing the college's athletic club (1923–8), he won fifteen national athletics championships, at 100 yards, 220 yards, 440 yards, 120 hurdles, 220 hurdles, and 440 hurdles; he also won a number of intervarsity titles at these distances, in addition to the half-mile and the discus. His victories at championships of the National Athletic and Cycling Association included 100 yards, 220 yards, 440 yards, 880 yards, and the long jump. At the 1924 Olympic games in Paris he represented Ireland in the 400 metre and 200 metre sprints, just missing a place in the final of the latter race. Captain of the Irish team in the 1928 Amsterdam Olympics, he again competed in the 200 metre and 400 metre competitions. In addition to athletics, he played Gaelic football, soccer, and rugby at UCD, playing on college teams that won the Collingwood cup (soccer, 1925), and the Sigerson cup (Gaelic football, 1923, 1929). In the 1927 intervarsity rugby game against TCD he scored a remarkable try in Lansdowne Road, and the following year he was a member of the St Vincent's Hospital rugby team that won the Dublin hospitals’ cup. He retained links with sport in UCD, serving as treasurer of the Athletic Union Council in the 1940s. He died 5 August 1973 in Dublin.
He married in England a fellow doctor, Constance, daughter of Charles Neville Cook and Florence Cook (née Taylor) of Dún Laoghaire, Co. Dublin; they had one son and two daughters, all of whom became medical doctors.