Domvile’s father, a Member for county Dublin in the Irish parliament, inherited both the Domvile and the Santry estates (from his kinsman, 4th Baron Santry [I]) in that county. This made his son, who retired from the army with the rank of captain on succeeding to the estates in 1810, ambitious of obtaining a revival of the barony of Santry. When he married the bishop of Kildare’s daughter in 1811 he was said to have ‘20,000 a year, fair good looks and nothing against him but a very disagreeable way of talking, a hesitancy that renders it difficult to understand him’.
Not long afterwards Domvile, who aspired in vain to an opening in county Dublin in 1817, was returned for Bossiney on the Mount Edgcumbe interest, placed at the disposal of administration; this was evidently a conciliatory arrangement instigated by Peel, whose brother had held the seat until the dissolution. Domvile was a silent supporter of administration. On 1 Mar. 1819 he was a defaulter ordered to attend on the 18th, but he voted against Tierney’s censure motion on 18 May. His applications to Peel and to the King in 1822 for a peerage were unsuccessful.