Irish-born Patrick ('Paddy') McMahon Glynn was a lawyer, politican and 'father of Federation' in South Australia. A member of the House of Assembly in the late 1880s and 1890s, he was a delegate to the Federation Convention in 1897-189, at which his enduring contribution was the reference to God in the Australian constitution's preamble. Glynn was elected to the House of Representatives in 1901 on a Free Trade platform and served in three ministries before his defeat in 1919. He returned to the law before he died in 1931. (Gerald O'Collins, 'Glynn, Patrick McMahon (Paddy) (1855–1931)', Australian Dictionary of Biography, National Centre of Biography, Australian National University, http://adb.anu.edu.au/biography/glynn-patrick-mcmahon-paddy-6405/text10949, published first in hardcopy 1983, accessed online 13 February 2019.)

The portrait appears to be from a collection depicting ministers (or attorneys-general) in South Australian goverments. Glynn was Attorney General in the Vabien Solomon government (South Australia's shortest) which was in office from 1-8 December 1899.