"We wrote history today," Green party politician Muhterem Aras said after being elected with a large majority as president (speaker) of the state legislature.
The south-western state had sent "a message of openness, tolerance, and successful integration," by electing her, she went on, promising to ensure a lively but fair debating culture in the chamber.
Aras, 50, is a tax accountant and financial affairs spokeswoman for the Greens in the wealthy southern state of Baden-Württemberg.
Her family moved from Turkey to Stuttgart, where her father found work at an elevator company and her mother worked as a cleaner.
She herself worked her way through the German education system before studying economics and founding her own tax advice firm.
Most members of the house from the right-wing populist Alternative for Germany (AfD) group refused to applaud as Aras concluded her maiden speech.
But Jörg Meuthen, who leads the AfD in the Stuttgart parliament and serves as the party's federal spokesman, dismissed the importance of her election for the party, which recently made limitations on the Muslim faith a central part of its party platform.
"We've always said that millions of people of Muslim faith are a part of Germany who live here, peacefully integrated," Meuthen said. "One of them is now speaker of the state parliament – so what?"
State lawmakers are expected to re-elect the Green party's Winfried Kretschmann as minister-president (governor) in another first later this week.
The Greens will govern as the largest coalition party with Chancellor Angela Merkel's Christian Democratic Union (CDU) as their junior partners.
It is the first time in the history of the Federal Republic that a party outside the CDU (plus its Bavarian sister party the CSU) or the centre left Social Democratic Party (SPD) has won the popular vote in a state election.