Mr Roxburgh has competed in the Challenge twice and has been course director for the Challenge's Lake Wanaka half for the past six years, including last month's event.
He succeeds Victoria Murray-Orr who has retired after nine years.
Mr Roxburgh was also operations manager for the Coast to Coast the weekend before the Challenge.
He told the Otago Daily Times he believed he could continue with both roles.
He hoped to build on what Ms Murray-Orr had achieved with the challenge.
"She's done a wonderful job and the event's been picking up every year with her guidance.
"So it's just rolling on with a bit of fine-tuning really.''
One issue he wanted to address was the level of sponsorship.
"Like all events, it's a struggle for monetary sponsorship, so we would really like to build on that.''
Mr Roxburgh said he was a born-and-bred Southlander who set up Adventure Southland some years ago and had a long involvement in triathlon.
