Born in Melbourne, he attended state schools before becoming a retailer of dental supplies.

He underwent military service from 1899 to 1901 and served in South Africa during the Second Boer War with the Victorian Mounted Rifles.

He held the seat until 1940, when he was defeated by Labor candidate Max Falstein.

[1] Between 1928 and 1958 Jennings served as National President of the Australian Dental Trade Association (ADTA), which now trades as the Australian Dental Industry Association (ADIA).

He remains that organization's longest serving federal president.