Montana Legislative Referendum 121 was a referendum held in Montana in 2012 that denied state funded services to illegal immigrants.^[1][2][3]

The electorate of Montana approved the measure in the 2012 general election by a vote of 378,563 votes for to 97,528 votes against.^[4] The Montana Immigrant Justice Alliance challenged the validity of the law shortly after it was approved by the electorate of Montana.^[5] In June 2014, a Montana State District Court invalidated significant portions of LR 121 on the grounds that LR 121 was an attempt to supersede a federal statute and an attempt to regulate immigration, a power specifically delegated to the federal government under the United States Constitution.^[6] The State of Montana has appealed the ruling to the Montana Supreme Court.^[7]