 Parry entered Parliament at a by-election in January 1913 following the death of the sitting Liberal member for Flint Burghs, James Woolley Summers.The constituency included Parry's home town of Mold where he was a prominent lawyer and he was elected with a majority of 211 votes over the Unionist, J H Roberts – as usual in these contests a reduced majority from the previous election when Summers had a majority of 509.The constituency disappeared in boundary changes in 1918 so Parry transferred to the county seat of Flintshire.