The New Orleans mayoral election of 1973 resulted in the reelection of Moon Landrieu to his second term as mayor of New Orleans. The primary round of voting was held on November 10; no runoff was required. Unlike the previous election, the Republicans did not field a challenger to Landrieu, and thus was automatically elected following the Democratic primary.
The 1973 elections were the last municipal elections in New Orleans held using the closed primary system. In 1975, Louisiana Governor Edwin Edwards signed a bill which changed all elections, except those for president, to an open primary system where all candidates regardless of party run on the same ballot. If one candidate does not receive an absolute majority (defined as 50 percent plus one vote), the top two finishers contest a runoff election.[citation needed]