The couple is super private about their relationship therefore it's unclear when they started dating.
Pajkovic is the daughter of Montenegrin actor Dragomir Pajkovic, who is a television star in her native country.
Holbrook was previously engaged to Elizabeth Olsen for a year prior to romance with his "baby mama."
The 'Logan' actor described the breakup as a "divorce" back in an interview in 2015.
He revealed how Olsen called him on the same day his best friend died to end their relationship.
The 36-year-old actor told, "On the same day that my best friend died, I got a call from my girl to tell me it was over."