His first feature was a supporting role in Scary Movie 4, playing 'Robbie Ryan'.

Mirchoff joined the cast of Desperate Housewives, playing Danny Bolen between 2009 and 2010.

Beau was also seen as a recurring character on NBC's period drama Aquarius and in indie thriller Poker Night opposite Ron Perlman and Giancarlo Esposito.

He is now known for playing the role of Jamie Hunter on The Fosters and now more recently their sister show, Good Trouble.

[citation needed] In March 2024, Mirchoff graduated from Oregon State University with a Bachelor's degree in environmental sciences.