On June 5, 2018, Omar filed to run for the United States House of Representatives from Minnesota's 5th congressional district after six-term incumbent Keith Ellison announced he would not seek reelection to that office. On June 17, she was endorsed by the Minnesota Democratic–Farmer–Labor Party after two rounds of voting. Omar won the August 14 primary with 48. 2% of the vote. The 5th district is the most Democratic district in Minnesota and the Upper Midwest, (it has a Cook Partisan Voting Index of D+26) and the DFL has held it without interruption since 1963. She faced health care worker and conservative activist Jennifer Zielinski in the November 6 general election and won with 78. 0% of the vote, becoming the first Somali American elected to the U. S. Congress, the first woman of color to serve as a U. S. Representative from Minnesota, and (alongside former Michigan state representative Rashida Tlaib) one of the first Muslim women elected to the Congress.