1918: 8 & 9 George 5 c.47: Parliament (Qualification of Women) Act
An Act to amend the Law with respect to the Capacity of Women to sit in Parliament.
[21st November 1918]
Be it enacted by the King’s most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, as follows:
Capacity of women to be members of Parliament.
1. A woman shall not be disqualified by sex or marriage for being elected to or sitting or voting as a Member of the Commons House of Parliament.
2. This Act may be cited as the Parliament (Qualification of Women) Act, 1918.
Further reading: Wikipedia