New Mexico's Deb Haaland and Kansas attorney Sharice Davids were elected the first two Native American women to serve in Congress.
She ran against and defeated Republican candidate Jennifer Zielinski, becoming the first congresswoman to wear a hijab.
For Tlaib, Tuesday's election marks the second time she will have made history in recent years.
"I did not expect to come to the United States and go to school with kids who were anxious about food as much as I was anxious about it in a refugee camp", Omar said in an interview last month.
Omar, 36, fled her homeland of Somalia at the age of eight and lived in a Kenyan refugee camp before immigrating with family to the United States.
Also Massachusetts, Democrat Ayanna Pressley will be the first woman of colour in her state's congressional delegation. She campaigned on a progressive platform and won the endorsement of the Democratic Party's fledging progressive wing, including Alexandria Ocasio-Cortez. Ilhan Omar, a Somali refugee, won a House seat in a heavily-Democratic district in the Midwestern state of Minnesota, where she will succeed Keith Ellison, himself the first Muslim elected to Congress.
The 42-year-old was born in Detroit to Palestinian immigrant parents.
Omar spoke during her campaign about her opposition to President Trump's travel ban against Muslim countries.
She has become "a source of pride for Palestine and the entire Arab and Muslim world", her uncle Bassam Tlaib told Reuters on Tuesday.
In California's 50th district, Ammar Campa-Najjar, a Palestinian-American who spent part of his childhood in Gaza and whose father served in the Palestinian Authority, was in a close race with incumbent Republican Congressman Duncan Hunter, early results showed.