蒙大拿州（英语：State of Montana）是美国西北部的一州，州名来自于西班牙语的「montaña」（山），此州的面积在美国名列第四大，然而相对之下，人口相当稀少，人口密度也相当低，经济上以农牧为主，作物主要有燕麦、大麦和甜菜，亦有重要的采矿和伐木业。

此州的西边有三分之一都是山脉，在东边则有三分之二还属于美国大平原的范围。原居民是美国原住民，在1864年成为了蒙大拿领地，1889年加入美国联邦，为排名第41顺次的州。该州也是第一个选出美国女国会议员珍奈特·雷金的州。在种族上，蒙大拿州有相当多的白人（89.5%），美国原住民则占有6.2%。尽管该州在政治上以共和党员占绝大多数，但州长Steve Bullock却是民主党人。

Montana /mɒnˈtænə/ is a state in the Western region of the United States. The state's name is derived from the Spanish word montaña (mountain). Montana has several nicknames, although none official, including "Big Sky Country" and "The Treasure State", and slogans that include "Land of the Shining Mountains" and more recently "The Last Best Place". Montana is ranked 4th in size, but 44th in population and 48th in population density of the 50 United States. The western third of Montana contains numerous mountain ranges. Smaller island ranges are found throughout the state. In total, 77 named ranges are part of the Rocky Mountains.