County Roscommon was a UK Parliament constituency in Ireland.
The constituency sent two MPs to Westminster from the Acts of Union 1800 until the constituency was split into Roscommon North and Roscommon South in 1885.
O'Conor was appointed a Lord Commissioner of the Treasury, requiring a by-election.
On petition, Goff was unseated and a by-election was called.
French's death caused a by-election