It caps a remarkable rise for the Gorseinon youngster, who made only one first-team league appearance last season, yet rose to become one of the mainstays of the Blues side as they won the EDF Energy Cup for the first time and reached the semi-finals of the Heineken Cup.
Not only that, he seamlessly moved from the Wales Under 20 side at last summer's IRB World Junior Championship tournament into the full Welsh team and will be the youngest member of Ian McGeechan's 2009 Lions tourists.
"To be experiencing all of this in my first season of senior rugby is just mad. It was great meeting up with all the different players and coaches from the other countries at the Lions gathering this week was a wonderful experience," said Halfpenny.
"When I first saw Ian McGeechan I just froze. I didn't think anyone would know who I was and that I would have to introduce myself to everyone, but they did know me.
"Then we had the team photographs. It was great to get that jersey on for the first time because it really makes you feel special."