The former OC star was confirmed to be part of the series reboot called The Hills: New Beginnings earlier this month. It is set to air sometime in 2019.
She headed out of a popular restaurant with Heidi on Tuesday night. The mother-of-one has been part of The Hills since it premiered all the way back in 2006.
The 32-year-old looked chic and sophisticated in a ruffled top underneath a black jacket and pants.
Heidi and Spencer, who just celebrated their son Gunner's 1-year-old birthday on the 1st, showed some major PDA while inside.
The happy mommy shared an adorable video of Gunner floating around in the pool on her Instagram earlier in the day. "Such a fun vacation!", she wrote while at a luxury hotel named Montage Laguna Beach.
Are you happy that Mischa joined The Hills? Sound off in the comments!