Hickson travelled in the Malay archipelago in 1885–1886. He was appointed Professor of Zoology at the University of Manchester in 1894 and was elected FRS in 1895. The Manchester Museum has many specimens of coral that came from Sydney Hickson, a specialist on corals. These include a number of type specimens of names published by Hickson and others, including Stanley Gardiner. Hickson's [https://archiveshub.jisc.ac.uk/manchesteruniversity/data/gb133-sjh papers] are held at the University of Manchester Library.
Hickson's daughter Sylvia Kema Hickson (married name Guthrie) became a paediatrician in Manchester.