Cavanough was born in Gosport England in 1762. He accompanied Phillip on the first expedition to Port Jackson from Botany Bay.  In March 1790 he was stranded at Norfolk Island when the Sirius was wrecked, he was discharged to become a settler on Norfolk Island.

Owen Cavanough met and married Margaret Darnell (also know by the names Darling and Dowling) while on Norfolk Island. On the 16 May 1791 he was located on 60 acres (Lot No 42) at Cascade Stream,  Phillipburn..  50 of his 60 acres was ploughable, of which he had cultivated 15 by October 1793.  He later sold this land.

The couple settled on their farm on  Norfolk Island where they had two children of their own, but sadly their first born Owen, died at 2 years of age and is buried on Norfolk Island.

In 1796 they returned to Port Jackson with the 2 children, one was William Green and the other Grace Cavanough, to live at the Hawkesbury. Owen acquired a boat which he used to transport grain and stores between Sydney and the Hawkesbury via Broken Bay. 

In January 1798, seven absconders captured him and his boat in Broken Bay, together with a smaller boat, both of which were taken out to sea.  Cavanough with the owner of the second boat and one of the absconders, who gave up the idea of escaping, were placed in the smaller boat and later reached safety. 

The absconders were eventually forced to give themselves up in March (two were hanged) and Cavanough's boat was returned to him.  By 1807 Owen and Margaret had five more children.

In 1803 Owen was granted 100 acres at Mulgrave Place and by 1806 farming was proving viable, although in 1809 he was working as a stockman.

In the mid 1800's he owned three hogs and had two acres sown in wheat and eight ready for planting maize.  The land was recorded as rented from a Mr. Boston.  He was on stores as were his wife and children.  Two years later Cavanough had 15 of 30 acres at Mulgrave Place sown in wheat, barley and maize with 14 bushels of maize on hand.  He, his wife, five children and a free servant were off stores; but he owed the government 14 bushels of maize and 12 of wheat. 

In 1820 Cavanough held land at Portland Head, in 1825 he was listed as a land holder in the Wilberforce district, recorded as formerly a seaman on "Ceres" (Sirius).  In 1828 he was farming 60 acres at Lower Portland Head, aged 66, his wife Margaret, then aged 61 was still with him.

At the age of seventy-nine, Owen accidentally drowned on 27 November 1841 at Wheeney Creek on the Hawkesbury.