Keller was born in Los Angeles, California and raised in Saint Paul, Minnesota.

She studied at St. Paul's Conservatory for Performing Artists and graduated from Carnegie Mellon University in 2014.
Keller played a minor role in the second season of Fargo.

In 2016, she was cast as the female lead in the TV series Legion.

Filmography:

​

Year			Film
2012			Still Adore You
2012			Flutter
2014			Hollidaysburg
2015			The Mentalist
2015			Supernatural
2015			Fargo
2016			Wig Shop
2017—2019			Legion
2019			The Society
2019			In the Shadow of the Moon
2020			Dirty John
2022			Tokyo Vice
2022			Butcher's Crossing
2022	ф		A Man Called Otto