He joined the First Australian Imperial Force at the start of World War I and served with the 2nd Light Horse Brigade in Gallipoli where he was wounded.
He returned to Australia in December 1918 with the rank of Captain having lost a brother to fighting in April of the previous year.
[1][2] Donnelly, representing the Labor Party,[1] unsuccessfully contested the seat of Wynnum at the 1932 Queensland election.
[3] He once again contested Wynnum three years later and this time he defeated the sitting member, James Bayley, of the Country and Progressive National Party.
[4] He only held the electorate for one term, being defeated by William Dart of the United Australia Party at the 1938 state election.