The 36-year-old actress -- who exchanged vows with her 48-year-old Orville co-star back in May -- filed for divorce on Monday in Los Angeles, according to court documents obtained by ET.
Both parties were ordered by the court to share financial information regarding their personal and communal assets.
The pair were seen together over the weekend at San Diego Comic-Con, where they attended a panel discussion on the upcoming season of their Fox sci-fi series. Palicki even posted a selfie to Instagram of her and Grimes at the event.
The event marked the one-year anniversary of the couple going public with their relationship at last year's Comic-Con, before revealing their engagement in January.
Palicki shared some snapshots of their wedding to Twitter back in May, writing, "Last night was truly amazing! I am so grateful for all the friends and family who made trip to celebrate with us, and to all of you for the kind words."
No grounds for divorce were cited in the recent court documents. The pair share no children. This is the first marriage for Palicki -- although she previously called off her engagement to ex Jackson Spidell in February 2017 -- and the third for Grimes.
ET has reached out to the stars' reps for comment.