The 2012 United States Senate election in North Dakota took place on November 6, 2012, concurrently with the 2012 U.S. presidential election, other United States Senate elections, United States House of Representatives elections, and various state and local elections. Incumbent Democratic-NPL Senator Kent Conrad decided to retire instead of running for reelection to a fifth term. Though each party endorses a single candidate in state conventions in the spring, ballot access for the general election was determined in a primary election held on June 12, 2012. Heidi Heitkamp, a Democratic-NPL former North Dakota Attorney General, won the open seat over Republican Rick Berg, North Dakota's at-large U.S. Representative, by a margin of 0.9%. Heitkamp outperformed President Barack Obama by 20.5%, the latter having lost North Dakota by 19.6% in the concurrent presidential election. Heitkamp's very narrow winning margin made it the closest race of the 2012 United States Senate elections. , this was the last time a Democrat won a federal and/or statewide election in North Dakota.

Democratic-NPL primary

The North Dakota Democratic-NPL Party held their state convention March 16–18, 2012, in Grand Forks. Former state attorney general and 2000 Democratic gubernatorial nominee Heidi Heitkamp was uncontested in seeking the official party nomination and was the only member of the party elected to appear on the state primary ballot.

Candidates

Nominee

Withdrew

Declined

Republican primary

North Dakota Republicans endorsed U.S. Representative Rick Berg at their convention, though general election ballot access is determined by a statewide primary election held on June 12, 2012. In contrast to state political tradition, declared candidate Duane Sand did not seek the party endorsement, trying instead to defeat Berg on the June primary ballot.

Candidates

Nominee

Eliminated in primary

Declined

Endorsements

Polling

Results

[Results by county:

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General election

Candidates

Debates

Fundraising

Top contributors

Top industries

Independent expenditures

In early October 2012, Crossroads GPS announced that it would launch a $16 million advertising buy in national races, of which four were this and three other Senate elections.

Predictions

Polling

Results

By county