The 23-year-old central midfielder has signed a four-year contract for an undisclosed fee and continues to club’s new policy of signing relatively unknown talent based on an in-house statistical model.
The club’s new head coach Marinus Dijkhuizen said: “I am delighted that Konstantin has chosen to join us at Brentford. He is a box-to-box midfield player who I think will add versatility to our squad.”
Kerschbaumer began his career with Rapid Vienna before a spell with First Vienna and then Europa League qualifiers for SKN St. Polten.
He only joined Admira in January having impressed for SKN in the first half of last season.
Kerschbaumer is Brentford’s fourth signing of the summer after French centre-back Yoann Barbet and midfielders Akaki Gogia and Ryan Williams.
Meanwhile, out-of-contract defender Alfie Mawson has signed for League One side Barnsley. Brentford may be due compensation because of Mawson’s age.