John P O'Donnell (born 1890; date of death unknown) was an Irish Australian soldier and poet, fl.
O'Donnell was born in Tuam, County Galway in Ireland in 1890, the son of an accountant in the National Bank.
He served in the Australian Army during World War I, arriving at Gallipoli on 25 April 1915.
He received an appointment to the staff of the Bank of Adelaide, and for some time lived with an uncle, the late Dr. Eugene Glynn.
In 1918 he was invalided home, during which time he wrote the last six poems of his only collection, dealing with the war from the perspective of an Australian.