The Electoral (Amendment) Act 1947 (No. 31) was a law in Ireland which revised Dáil constituencies. The new constituencies were first used for the 13th Dáil, elected at the 1948 general election on 4 February 1948. This Act repealed the Electoral (Revision of Constituencies) Act 1935, which defined the constituencies since the 1937 general election. It also increased the number of seats in the Dáil by 9 from 138 to 147. It was used at the 1951, 1954 and 1957 general elections.