He was aide-de-camp to Sir Thomas Brisbane, governor of New South Wales and explored the Murrumbidgee River and Monaro (New South Wales) district with Captain Mark Currie. Ovens was born in Street Catherine, Fermanagh, Ireland and joined the 73rd (Perthshire) Regiment of Foot of the British Army in 1808. He travelled with the regiment in 1810 to the colony of New South Wales.
He returned to England in October 1811 and soon transferred to the 74th (Highland) Regiment of Foot under Thomas Brisbane.
Ovens returned to New South Wales when Brisbane was appointed governor and was made acting chief engineer In October 1825 Ovens assisted John Oxley to survey Twofold Bay.
Brisbane employed Ovens as his private secretary and promoted him to major.