Appointed the chief executive officer in 2018, he was tasked with leading a reset of the business to turn around Fonterra's financial performance and rebuild farmers' trust.
Hurrell said while it's not an easy decision to step away, the time is right for the co-op and him personally.
"When I took the role of CEO, I understood our financial results are not just numbers but the livelihood of thousands of New Zealand farming families," he said.
"I have always felt a great sense of responsibility to do what's right for farmers and I believe the co-op is now in a really good place."
Hurrell said Fonterra is entering the next phase in its strategic implementation which marks a natural turning point for a new leader to step in.
The co-op's sale of its consumer brands to French dairy giant Lactalis went unconditional earlier this month
"I know that the business will be in good hands. There's an exceptional team of people who will carry the co-op forward and continue to drive value for farmers," Hurrell said.
Fonterra board chair Peter McBride said Miles has a six month notice period, which enables an organised leadership transition.
"Board and management regularly discuss succession as part of good governance practices. We are confident we can run a robust selection process and appoint a new CEO in the coming months."
He said he echos the sentiment of farmers when saying that Miles will leave with sincere thanks for his 25 years of loyalty and best wishes for the future
"Under Miles' leadership the team has done that and more. From day one, Miles was able to unite the team under a single purpose and drive performance right across the business, setting the co-op up for the future," McBride said.
"On behalf of the Board, I thank Miles for his courageous leadership. He has overseen a significant strategic reset, focused on getting the co-op back to its core strengths. In doing so he has helped lift Fonterra's financial discipline and built the strong foundations the co-op has today."
Peters slams Hurrell
New Zealand First leader Winston Peters has weighed in on Hurrell's resignation, saying his departure was expected after the sale of "iconic Kiwi dairy brands" to a foreign owned company.
"CEO Miles Hurrell has resigned and will leave once his bonuses are paid," Peters said on social media.
"We said this exact thing would happen in our open letter to farmers last year - he of course denied it."
Peters said Hurrell had "sold off" almost every consumer brand since he started, "leaving Fonterra as a commodity price taker, not a market maker".
"Their decision leaves serious questions for New Zealand about what we must do to protect dairy manufacturing in our country as a result of Fonterra's dereliction of duty."
Peters said the last time a Fonterra CEO resigned, Theo Spierings in 2018, he was paid out a "ridiculous" $4.67 million after being paid a total of $43m in just seven years in the role.
Peters questioned how much Hurrell would be "paid out".
