Former vice president and presumptive nominee Joe Biden won the primary with more than 74% of the vote and won all delegates except one, crossing the necessary majority of 1,991 delegates to officially win the Democratic nomination three days later during the vote count,[1] while senator Bernie Sanders narrowly missed the threshold for statewide delegates with 14.7%, winning one delegate, and senator Elizabeth Warren received the remaining 8%.

Montana was one of seven states and the District of Columbia to vote on June 2, 2020, in the Democratic primaries, along with Indiana, Maryland, New Mexico, Pennsylvania, Rhode Island and South Dakota.

The 19 pledged delegates to the 2020 Democratic National Convention were allocated proportionally on the basis of the primary results.

Of these, 6 and 7 were allocated to the eastern and western districts and another 2 were allocated to party leaders and elected officials (PLEO delegates), in addition to 4 at-large delegates.

Polls with a sample size of <100 are marked in red to indicate a lack of reliability.