Commencing in July, the expansion will also provide an opportunity to introduce measures for increased sustainability, the statement said.
"I am really excited to be joining the team at Whakatāne Mill and really looking forward to the challenge of overseeing this new, exciting phase in its journey," Hooper said.
Executive chairman Ian Halliday said Hooper's appointment was an important milestone for WML, after it successfully avoided the threat of closure last year.
Former owner SIG Combibloc had struggled to keep the mill competitive and sold it to Power Paperboard Limited (PPL), a consortium of Irish and European investors, averting the loss of more than 170 jobs.
"Ron is a driven and motivational leader, with the ideal background to lead the company and team through the expansion. His focus will be on improved performance based on strategy development, top-line growth and bottom-line management.
"We are delighted to welcome him to the team," Halliday said.
Whakatane Mill is a significant employer and contributor to Whakatāne and the Bay of Plenty's local economy. It has been producing paper and paperboard for 80 years.