Powell, a professional wakeboarder, first met the wildlife warrior, who turned 18 on July 24, in November 2013 while he was visiting the Australia Zoo.
After friendship turned into romance, the pair embarked on a long-distance relationship, relying on Skype and FaceTime to keep in touch while they're apart, Irwin previously told WHO.
"I'm really happy with our relationship and I think we'll just continue to have fun," the young conversationalist explained to ET. "It's just nice to have someone there no matter what."
Irwin gushed about her beau, explaining that his thoughtfulness is one of the things she likes most about him.
"It's nice when you find somebody who's just endlessly kind and understands you and is really like-minded. I always get really excited," she told ET. "I'm really blessed and grateful to have him in my life."
Powell flew to Australia from the UK to help Irwin celebrate her 18th birthday at Australia Zoo on July 24.