Auguste O'Kelly (13 July 1829 – 16 February 1900) was a Franco-Irish music publisher in Paris between 1872 and 1888.
Auguste O'Kelly was born as Louis Auguste Kelly in Boulogne-sur-Mer as the second son of the Dublin-born piano teacher Joseph Kelly (1804–1856). His brothers included the composers Joseph O'Kelly (1828–1885) and George O'Kelly (1831–1914). Around 1835 the family moved to Paris, where they lived in the Faubourg Poissonnière area of the 9th arrondissement. Nothing is known of his early education, but it may be presumed that he received piano lessons by his father. His name appears in the membership lists of the Association des artistes musiciens for four years from 1850 and again from 1862 to 1864. Like his brothers, he went to Boulogne-sur-Mer in 1859 to have his name officially changed from Kelly to O'Kelly. The manufacturing register of the Paris piano maker Pleyel suggests that he sold pianos for them (or at least acted as an intermediary between the manufacturer and dealers) mainly between 1867 and 1871.
In May 1872 O'Kelly took over the music publishing business Magasin de Musique du Conservatoire on 11 rue du Faubourg Poissonnière in the 9th arrondissement of Paris. This was active until late 1888 (see below). From 1872 until 1881 he also ran a piano shop at the same premises, where he sold pianos that were branded with the name of his publishing business. Most likely, however, he was not a piano maker but a dealer only.
In October 1872 his son Gustave O'Kelly (1872–1937) was born, the (unmarried) mother being Juliette Patinier, at 25 years of age 18 years younger than Auguste. She died less than two years later (in May 1874). Auguste then married Fanny Vincent (1827–1901) on 3 December 1874.
After O'Kelly closed down his publishing business he was active in various functions at the Conservatoire in Paris, including as Bibliothéquaire-adjoint and as secretary of the committee for admissions et propaganda. He retired from these positions in 1892 and appeared forthwith as secretary of the Association des artistes musiciens. He died in Paris, aged 70, on 16 February 1900 in the home of his son in Avenue Trudaine, 9th arrondissement. His funeral service was held in Notre-Dame-de-Lorette, and he was buried on the Père Lachaise cemetery, where the grave is still extant (in Division 74).