Launcelot Jefferson Percival KVCO (22 May 1869 – 22 June 1941) was an Anglican priest who in addition to various parish posts served in the Ecclesiastical Households of Queen Victoria, King Edward VII, King George V, King Edward VIII and King George VI.

Percival was also a noted sportsman in his early adult life and was an international rugby union forward who played club rugby for Oxford University and Rugby. Percival played international rugby for England and was an original member of invitational team, the Barbarians.

Percival was born in Clifton, Bristol in 1869 to John Percival and Louisa Holland. He was educated at Clifton College, of which his father was headmaster. Percival followed his father later in life when he matriculated to Trinity College, Oxford, as after leaving Clifton, John Percival had taken the role of President of Trinity College.

Percival left university with a master's degree and took Holy Orders. By 1899 he was resident chaplain to the Bishop of London, and on 28 February 1899 he was appointed an Honorary Priest in Ordinary to Queen Victoria, his first entry into the monarch's Ecclesiastical Household. By 1905 he was also rector of St James's Church, Fulham and on 3 November he was promoted to Priest in Ordinary to the king. In 1910 he became the rector of St Mary's, Bryanston Square in London. On 6 January 1922 he was appointed Precentor of the Chapel Royal, and on 6 February 1923 domestic chaplain to the king. On 3 March 1924 he was appointed Chaplain of the Venerable Order of Saint John. In 1931 Percival was made Deputy Clerk of the Closet (and sub-almoner), and on 20 July 1936 was reappointed to the post after the accession of Edward VIII and again on 2 March 1937 under George VI after Edward's abdication. In the 1936 New Year Honours he was appointed Knight Commander of the Royal Victorian Order. In 1937 he was appointed Precentor of the Chapel Royal for the second time, this time he held the post until his death in 1941. He was succeeded by Revd Wallace Elliott.

The National Portrait Gallery in London holds two photographs of Percival, both taken in 1931 by one of Alexander Bassano's photographic studios.

Percival first came to note as a rugby player when he represented Oxford University whilst studying at Trinity. Although a forward, Percival had a good reputation for scoring tries, mentioned as scoring twice for an invitational priest's team in George William Erskine Russell's 1921 collection of essays Afterthoughts and in the 1891–92 season for Oxford scored a "remarkable try" against Blackheath when he dribbled the ball almost the entire length of the pitch before punting the ball over the opposing fullback to score.

One of Percival's most notable matches for Oxford was the 1889 encounter with the touring New Zealand Native football team. The match was played on 21 February, Oxford winning 6–0.

Percival played in two Varsity Matches against Cambridge University in 1889 and 1891 to win his sporting 'Blues'. His first Varsity game ended in victory, with Oxford winning by a goal and two tries to nil, Percival scoring one of the tries after a scrummage close to the Cambridge line. Percival was absent from the 1890 team, after being forced to stand down after an accident, but returned to the Oxford squad in 1891. Oxford began the 1891 game as favourites, with a very strong forward pack in tremendous form, but lost the match to late Cambridge pressure.