Greenwich was a constituency in south-east London, which returned at first two, then one member (MP) to the House of Commons of the UK Parliament. It existed from 1832 to 1997. Elections used the first past the post system; when this elects more than one member, it is sometimes called plurality-at-large voting.

The 1868 United Kingdom general election was the first after passage of the Reform Act 1867, which enfranchised many male householders, thus greatly increasing the number of men who could vote in elections in the United Kingdom. It was the first election held in the United Kingdom in which more than a million votes were cast; nearly triple the number of votes were cast compared to the previous election in 1865.