O'Loghlin was a member of the South Australian Legislative Council from 1888 to 1902, representing the Northern District, and was Chief Secretary under Charles Kingston from 1896 to 1899.

[1] He returned to state politics in 1910–1912, winning the South Australian House of Assembly seat of Flinders for Labor, but losing after one term.

O'Loghlin next became a wheat-buyer for the millers W. Duffield and Co. of Gawler; and when that firm was amalgamated with the Adelaide Milling and Mercantile Company he was appointed their agent at Terowie.

While there, he and a Mr. Dawson, who had previously been editor of the Burra Record, founded the Terowie Enterprise and North-Eastern Advertiser, and subsequently became sole proprietor.

O'Loghlin's retained a great popularity in the Northern District, and at the end of his term and he stood for re-election in 1892 he was returned at the head of the poll.

[4] In 1913 he was again a Labor candidate for the Senate, and was returned at the head of the poll, with John Newland and William Senior, and held his seat for six years.

[7][8] Soon after the war broke out in 1914, though well past the fighting age, he had volunteered for overseas service, and in 1915 was sent as an officer commanding reinforcements for the First AIF to Egypt, Gallipoli, and France.

He left a widow, three sons, who were attending Christian Brothers' College, and one daughter, who was a pupil at the Convent of Mercy school in Angas Street, Adelaide.