Brand and Isabella, who is the sister of Jordana Brewster, were photographed hand-in-hand while on a stroll in Los Angeles earlier this week.
The Brand X host later appeared on The Howard Stern Show and was asked if he is in fact dating Isabella.
"Some things in the newspaper aren't true," Brand responded at first.
Stern pressed the issue further, questioning: "That's not true at all?"
"That's true, actually," Brand answered, adding of his romantic life: "At the moment I'm kind of enjoying the freedom of it."
The Get Him to the Greek actor refrained from speaking further on the relationship, but did say that he has "nothing but love" for ex-wife Katy Perry.
"She's a good person," Brand said of his former spouse.
Perry and Brand were formally granted a divorce this week after complying with a six-month waiting period.