The 1911 Arfon by-election was a parliamentary by-election held on 11 February 1911 for the Arfon division in Caernarvonshire in North Wales, a constituency of the British House of Commons. It was the first by-election to be held after the December 1910 general election.
The by-election was held because the sitting Liberal Member of Parliament (MP) William Jones had been appointed as a Junior Lord of the Treasury in H. H. Asquith's Liberal government, and until the 1920s MPs appointed to positions in government had to seek re-election. Jones had held the seat since the 1895 general election, and at the by-election he was re-elected unopposed.
Jones died in 1915, triggering another by-election
! scope="col" colspan="2" style="width: 130px"|Party
! scope="col" style="width: 17em"|Candidate
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! scope="col" style="width: 3.5em"|%
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! colspan="3" style="text-align:right;" scope=row | Registered electors
References.
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