The United Kingdom of 1975 was a referendum held on 5 June, 1975 in the whole of the UK over whether there was support for the UK to stay in the European Economic Community, which the UK had entered in 1973, under the Conservative government of Edward Heath. When Labour won the 1974 general election, Harold Wilson promised a referendum over whether to stay in the EEC.
to be written
The electorate were asked to vote yes or no: 'The government have announced the results of the renegotiation of the UK's terms of membership of the European Community. Do you think that the UK should stay in the European Community?'
| Yes votes | Yes votes (%) | No votes | No (%) | Turnout (%) |
| 17,378,581 | 67.2 | 8,470,073 | 32.8 | 64.5 |