30 Welsh athletes have made been selected for Team GB, including Dai Greene, Helen Jenkins, Hannah Mills and Tom James.
The First Minister will be at the ceremony. He said:
"I want to wish every single Welsh athlete who has made the grade for TeamGB pob lwc. I have no doubt they will make all of us proud as they represent both Wales and the UK in the greatest sporting event in the world.
"The competition will be the culmination of the years of blood, sweat and tears so lets hope they bring home the medals. The medal count from Beijing was exceptional and matching it would be incredible - improving it the stuff of dreams."
Sports Minister Huw Lewis, who has recorded a video message wishing the team luck, added:
"The 30 Welsh competitors who will be taking part in the Olympic Games have already made Wales very proud. I wish every one of them the best of luck for the weeks ahead as they look to etch their names in history and I hope that their achievements will inspire a whole generation of people to get involved in sport themselves."