The 17-year-old will join Hamilton's Te Mania Shelford (18). She will contest the women's under-57kg class, while Murdoch will compete in the men's under-60kg class.
For the Kaikorai Valley College year 13 pupil it is an opportunity to put all his hard training into action.
"After putting everything into my training to be the best I can be physically and mentally, I love it when it's finally time to get in the ring with my opponent and implement my fight plan," he said.
"Travelling to Buenos Ares with the New Zealand team will be an awesome experience that will help me grow as a boxer and, of course, I'm hoping to bring home a medal."
Murdoch's selection hung in the balance for a while. He was defeated by Australian Jake Clauge in the final at the Youth Oceania Boxing Championships in Samoa earlier this year.
Had he won the fight, he would have automatically qualified for the tournament. Instead he had to hope a spot would open up and the selectors would recognise his potential.
Having cleared that hurdle, Murdoch's coach, Bryan Usher, is confident his young charge has the work rate and ability to reach the medal rounds.
"He is very, very good and getting better," Usher said.
"I think his prospects are very good. He has had 32 bouts now, he's been overseas a couple of times and he has boxed against international competition.
"I'd say he has every chance of getting through to the medal rounds."
Murdoch, who has a long list of junior titles, is from a fighting family. Brother Shem Murdoch is a professional MMA athlete and has been instrumental in helping his sibling prepare.
They pair train together and Murdoch's work ethic and discipline are great assets, Usher said.
"Kasib has an extremely high work rate in his training and in his boxing. It is unusual for someone his age to be that disciplined in training."
Usher described Murdoch as "a go forward boxer who uses angles well" and likes to cramp his opponents.
"We'd like him to exhaust his amateur options but his style is well-suited to the professional ranks if that is what he would like to do.
"The world is his oyster, really. It is all open to him."
The third edition of the Youth Olympics will be on October 6-18 in Buenos Aires.
