Davids, 38, of Kansas, is an attorney by training and a former mixed martial arts fighter. She is also openly lesbian, in a state that is traditionally conservative. She defeated Republican incumbent Kevin Yoder.
Haaland, 57, of New Mexico, beat Janice Arnold-Jones, a Republican, and Lloyd Princeton, a Libertarian.
The two women were among a record number of Native Americans who ran in the midterm elections for congressional seats, governor's offices, state legislatures and other elected posts.
"Strong, Resilient, Indigenous," reads the t-shirt worn by Davids in one of her campaign ads for election in the state's 3rd congressional district, which includes Kansas City and its southern suburbs.
Haaland, a member of the Pueblo of Laguna tribe, is a well-known community activist in her solidly Democratic district, working tirelessly to encourage Native Americans – who make up 2% of the US population – to vote.
She cut her teeth working as a volunteer for John Kerry's presidential campaign in 2004 – making endless cold calls to rally Native Americans to vote.
Since then, she has not stopped campaigning: she worked full-time as a volunteer for Barack Obama, and on dozens of local and state campaigns. She ran for lieutenant governor and served one term as the state party chair.
"We need real people who are talking about our issues and know what it feels like," Haaland told Agence France-Presse in an interview ahead of the elections, in which she ran in New Mexico's 1st congressional district seat.
"We have people in Congress right now who... don't know what it's like" to be without food or proper health care, she said.
She said although her disdain for President Donald Trump's policies on immigration, health care and other issues motivated her to run, that was not the only reason.