John O'Mara (1806-1867), merchant, office holder, was born in Waterford, Ireland, in 1806 and settled in Newfoundland. On 3 November 1831, he married Mary Allen (1813-1854), daughter of Mary (Shannon) and Michael Allen, who owned the St. John's farm known as Allen Dale. The O'Maras had twelve children. He died on 28 July 1867, and was buried in Belvedere cemetery.
O'Mara's business interests were diverse, and included general merchandise, shipping and the seal fishery. O'Mara was active in the Liberal party, and held several offices, including commissioner of roads for St. John's (1847), health warden (1847), and Roman Catholic Central Board of Education trustee(1853). O'Mara was also active in the Benevolent Irish Society (BIS).
David William O'Mara (1846-1884), magistrate, was born in St. John's in July 1846, son of Mary (Allen) and John O'Mara. He married Mary Elizabeth Geddes in 1875; they had seven children. He died at Ferryland on 31 August 1884.
After completing his education in St. John's, O'Mara studied law in Dublin, Ireland. He was appointed justice of the peace for Ferryland District in 1873, and served as justice and stipendiary magistrate for Ferryland, where he resided until his death. O'Mara also served as the returning officer for the 1878 general election.
John Thomas O'Mara (1851-1893), pharmacist, was born in St. John's, son of Mary (Allen) and John O'Mara. He married Mary Josephine Murphy (1808-1879); they had eleven children. John O'Mara died on 26 May 1893.
O'Mara apprenticed under the Scottish pharmacist, Thomas McMurdo. In 1874, he established his own pharmacy on east Water Street, St. John's, reportedly the first pharmacy opened by a native Newfoundlander. The pharmacy was lost in the Great Fire of 1892. O'Mara immediately reopened his business in his wholesale warehouse on King's Road; he later relocated to Rawlin's Cross. O'Mara was active in the BIS and was the first native Newfoundlander to be elected president of the Society.
Peter Alban O'Mara (1881-1964), pharmacist, was born in St. John's, son of Mary Elizabeth (Geddes) and David William O'Mara. He married Margaret Feehan Cooney; they had ten children. He died on 30 December 1964.
In 1906, O'Mara acquired the West End Drugstore, located on Water Street West, St. John's, and expanded the premises in 1908. The building is now a pharmacy museum, Apothecary Hall, which also houses the Newfoundland Pharmaceutical Association Archives. O'Mara was a member of the Rotary Club, Knights of Columbus, City Club and BIS.