Stephen T. Olney was born on Feb. 15, 1812, in Burrillville, R.I., and received his education in Providence. He started work in the counting house of Isaac B. Cooke & Co., which was probably located in Augusta, Georgia. Later he returned to the Providence area and started the Wauskuck Co., a wollens firms, with Jesse Metcalf. The business made Olney a wealthy man, and he devoted some of his wealth to the prusuit of his botanical interests. He published a catalogue of Rhode Island plants in connection with the Providence Franklin Society in 1845, with further additions in 1846-1847. He made collections of algae from 1846 to 1848 that served as the basis for his published in 1871. He became especially interested in the study of Carex and developed into an expert in the area. His publications on Carex include the Carex section of Sereno Watson's Botany (1871) in the Report of the Geological Exploration of the 40th Parallel led by Clarence King. He built up a private herbarium and botanical library and carried on a broad botanical correspondence.

In his later years, Olney went into a decline: W.W. Bailey wrote that he "was an invalid and incapacitated for business during the last years of his life," and Asa Gray wrote that the end of his life was "obscured and afflicted by mental trouble." Olney died a bachelor on July 27, 1878. He left his herbarium, library and correspondence to Brown University and also gave substantial sums of money toward botanical studies at Brown.