Tlaib, a Detroit Democrat, will be the first Muslim woman to serve in Congress. Minnesota Rep. Keith Ellison, a Detroit native, became the first Muslim elected to the chamber in 2007 and, along with Rep. Andre Carson, D-Indiana, is one of two Muslims now serving in the U.S. House.
Joining Ms Tlaib in Congress will be Ilhan.
Both women - Ilhan Omar, 37, and Rashida Tlaib, 42 - are Democrats from the Midwest and outspoken advocates of minority communities that have found themselves in the sights of U.S. President Donald Trump's anti-immigrant policies.
The Palestinian-American won the Democrat primary for the seat in August with around a third of the total vote share.
Ilhan Omar won the U.S. House race in the 5th Congressional District.
"My success is not only for me but for every Somali, Muslim and minority group, particularly the young girls in the Dadaab refugee camp, where I lived before coming to the US", Ms Omar declared.
She beat Republican Jennifer Zielinski to take Keith Ellison's seat, which he vacated to run for Minnesota attorney general.More news: Lakers validate LeBron's proclamations of progress with win at Portland
The oldest of 14 children, Tlaib was born to a family of Palestinian immigrants in Detroit, where her father worked at a Ford Motor Co plant.
"We changed the course of history at a time we thought it was impossible".
In August, she emerged as the victor of a Democratic primary for a seat vacated by John Conyers, a longtime liberal lion who stepped down in December amid sexual harassment allegations and failing health.
Ellison was the first Muslim elected to Congress, in 2006.
With no Republican challenger in the race, Tlaib's election on Tuesday became a formality.
She campaigned on a platform calling for free tuition and promising to fight to expand Medicare coverage to all Americans. Tlaib ran unopposed, but fended off a late write-in challenge from the woman she defeated in the primaries.
She also has been mindful of the historic nature of her candidacy. "And that if you just believe in the possibility of someone like me", Talib added.