The City of London by-election, February 1906 was a parliamentary by-election held on 27 February 1906 for the British House of Commons constituency of City of London, which covered the "Square Mile" which was the United Kingdom's traditional financial district. The seat had become vacant on the resignation of Alban George Henry Gibbs, one of the constituency's two Conservative Members of Parliament (MPs). Gibbs had resigned in order to provide a safe seat for Arthur James Balfour. He would go on to succeed his father, Hucks Gibbs, as Baron Aldenham the following year.