"Across the country we are making choices to maximise the likelihood of the change in government that New Zealanders are calling for. Our decision won't have any material effect on the campaign that Labour is running".
Woodley, who has ancestry from Tuhoe and the West Coast, is a former army officer with a Masters in International Relations.
He said he would be "running hard in the democratic competition for the party vote in Ohariu".
"I have stood in the electorate before, am a resident of Johnsonville within the electorate and am fully across all of the local issues.
"The difference now is that I will have more opportunities to highlight the unique values that a Green Party has to offer more directly to Ohariu voters.
"For 25 years the Green Party has been focused on practical solutions to the country's most important issues. We have always led from the front and set the political agenda, giving a voice to the environment and to those who are struggling."
Woodley's biography on the Greens website says his interests include transport, energy, community safety, police, justice, emergency management and education.
In the 2014 election Woodley won 2764 votes, or 7.5 per cent, compared to National's Brett Hudson who won 6120 votes, Labour's Virginia Andersen who took 12,859 and United Future's Peter Dunne who won the electorate with 13,569.
But the number of people who gave the Greens their party vote was double Woodley's candidate vote at 5623, giving them 15 per cent of the total. Fifty percent of the Ohariu party vote went to National.
Labour Party general secretary Andrew Kirton said the Greens informed Labour this afternoon that Woodley was standing, "which is consistent with our Memorandum of Understanding".
"It was actually not unexpected - we have a friendly contest for the party vote."
He said it had been entirely the Greens' decision not to stand a candidate this year and they had no agreement with Labour on the matter.
Kirton said nothing would change for O'Connor, who when Dunne stepped down said he wanted to focus on being "the best candidate possible to become a good MP like Peter [Dunne] was. Nothing changes there."
The latest poll, on TVNZ's Q+A, had Dunne at 34 per cent and O'Connor at 48 per cent. People are "recalibrating" now that Dunne has stepped down, Kirton said, and were looking closely at O'Connor as a local MP.
United Future also announced its new candidate for Oharui today - Bale Nadakuitavuki.
"It's an absolute honour and a privilege to stand for the people of Ohariu," he said in a statement.
"The values and principles that we as United Future firmly stand for, stand strong within me as our candidate for Ohariu."
Nadakuitavuki grew up in the electorate and has lived there for 20 years.
"I am very keen on serving the people of Ohariu with distinction and honour should you vote for me," he said.
His nomination signalled a new era for the party, he said.
"Let us not forget what Peter has stood for but let us now look forward with hope to what we can continue to offer as a party for the people of Ohariu."
But twice as many Ohariu voters gave their party vote to the Greens. Fifty percent of the Ohariu party vote went to National last election, while the Greens won 15 per cent or 5623 votes.