Dionysius Lardner "Dion" Boucicault /ˈdaɪˌɒn ˈbuːsɪˌkoʊ/[1] (né Boursiquot; 26 December 1820[2] – 18 September 1890) was an Irish actor and playwright famed for his melodramas.

The New York Times hailed him in his obituary as "the most conspicuous English dramatist of the 19th century,";[3] he and his second wife, Agnes Robertson Boucicault, applied for and received American citizenship in 1873.

[4] Boucicault was born Dionysius Lardner Boursiquot in 1820 Dublin, where his family lived on Gardiner Street.

Anne was married to Samuel Smith Boursiquot, of Huguenot ancestry,[5] but the identity of Dion's father is uncertain.

[8] In 1828, Lardner was elected as professor of natural philosophy and astronomy at University College, London, a position he held until he resigned in 1831.

There is a gap of two years in the record, when Fawkes believes Boucicault may have attended Rowland Hill's Bruce Castle School, as stated in the Dictionary of National Biography.

[9] When Boucicault was in his late teens, his mother persuaded a cousin, Arthur Lee Guinness, to give her son a job as a clerk in the Dublin brewery.

First produced at Covent Garden on 4 March 1841, its cast included such well-known actors as Charles Mathews, William Farren, Mrs Nesbitt and Madame Vestris.

[13] Boucicault rapidly followed this with a number of other plays, among the most successful being The Bastile [sic], an "after-piece" (1842), Old Heads and Young Hearts (1844), The School for Scheming (1847), Confidence (1848), and The Knight Arva (1848), all produced at Her Majesty's Theatre.

[14] He had further great successes with The Corsican Brothers (1852, for Charles Kean) and Louis XI (1855), both adaptations of French plays.

There he produced at the Adelphi Theatre a dramatic adaptation of Gerald Griffin's novel, The Collegians, entitled The Colleen Bawn.

[20] Boucicault's next marked success was at the Princess's Theatre, London in 1864 with Arrah-na-Pogue in which he played the part of a County Wicklow, Ireland carman.

W. S. Gilbert referred to the notable actor in the libretto of his 1881 operetta Patience in the line: "The pathos of Paddy, as rendered by Boucicault".

[25] He wrote the melodrama Contempt of Court (poster, left) in 1879, but he paid occasional visits to London and elsewhere (e.g. Toronto[26]).

His uncanny ability to play these low-status roles earned him the nickname "Little Man Dion" in theatrical circles.

His oldest son was killed in the Abbots Ripton rail accident on the East Coast Main Line in England in 1876.

[33] Towards the end of this tour, he suddenly left Agnes to marry Josephine Louise Thorndyke (c. 1864–1956), a young actress, on 9 September 1885, in Sydney.

[33] This aroused scandal on both sides of the Atlantic Ocean, as his marriage to Agnes was not finally dissolved until 21 June 1888, by reason of "bigamy with adultery."