Panettiere, 24, is one of the stars of ABC's primetime country music drama “Nashville.” She met Klitschko, 37, in 2009 at a book party and the pair dated until May 2011.
They split up for some time but they were back together by last spring.
"It's like the 2.0 version," Panettiere said of their romance the second time around.
"I've always had great relationships and stayed really good friends with the guys I've dated. It blows my mind sometimes that us getting together has gotten so much attention. It's like, Really? This is breaking news?"
In a surprise twist, the news about Panettiere’s engagement broke while she had a live boa constrictor wrapped around her body.
After she walked out with the snake, co-host Kelly Ripa remarked, "I'm sort of distracted, not just by the snake, but there's a very large diamond ring on your ring finger. ... I'm not sure if you want to announce anything. ... Does that signify anything, is that a promise of something?”
Panettiere responded, "It might be. ... I mean, I think it speaks for itself."
When asked directly, "Are you engaged?" Panettiere said, "I am.”
The two have not settled on a date yet because of Panettiere’s busy schedule.