Louis Béguet was an all-around athlete who won a silver medal in rugby football at the 1924 Paris Olympics. In rugby he competed for Stade Nantais Université Club from 1920-28, but he also played with Racing Club de France in 1921-24, and Paris Université Club in 1924/25. Béguet was capped 10 times for France in rugby. He was 1923 French Champion in the hammer throw and competed against Britain that year in an international. In athletics he represented Racing Club de France. Béguet was also a top French golfer and tournament level tennis player.
Béguet was a career military man, who joined the 65th Infantry Regiment of Nantes in 1914. He left the military in 1930, and then worked for Mobil Oil until World War II, when he re-joined the French Army, serving as a captain from 1939-45, during which time he was briefly held as a prisoner-of-war.