At a meeting in Winton last night, National Party members returned the one-term MP as the party's nominee for the 2017 general election over challenger Simon Flood (52).
In a statement issued by the National Party last night, Mr Barclay (26) said he was thrilled with the result.
The selection contest divided the normally staid electorate, capping a difficult year for Mr Barclay. Sources in the electorate spoke of a toxic and acrimonious contest.
Last night, a member who supported Mr Flood told the Otago Daily Times that his supporters were ''mortified'' by the result.
Allied Press editorial staff member Mark Price, who was at the meeting, said most of the audience stood to clap and cheer the result. More than 100 people attended.
''There was definitely a faction there that wasn't happy with the result,'' he said.
Mr Price said Health Minister Jonathan Coleman addressed delegates while they waited for the vote count.
''[Dr Coleman] said Todd had done a great job in Parliament,'' Mr Price said.
Fellow National MPs Todd Muller (Bay of Plenty), Matt Doocey (Waimakariri), Jami Lee-Ross (Botany) and Sarah Dowie (Invercargill) were also at the meeting to show support for Mr Barclay.
It is understood Glenys Dickson, the long-serving Gore electorate secretary who resigned early this year after a dispute with Mr Barclay, was a voting delegate in the contest.
A police investigation was undertaken into an allegation the rookie MP made a secret recording of the former electorate staff member.
This month the police said Mr Barclay would not be prosecuted because of ''insufficient evidence''.
Mr Barclay's electorate chairman, Stuart Davie, resigned in March, saying his position was untenable.
Mr Barclay apologised in March for publicly releasing the resignation letter of another of his staff, Barbara Swan. At the time, he acknowledged he had made mistakes in his first term.
Ill feeling in the electorate did not abate and, ultimately, spurred a selection challenge from a highly regarded candidate.
It is understood Mr Flood's strongest support was in Queenstown and Gore, while delegates from Winton, Balclutha and Mossburn favoured the sitting MP.
Mr Barclay's majority in 2014 was 14,886 votes.
''One of the great things about National is the democratic process we run, so I want to thank all my supporters for giving me the opportunity to continue to represent them,'' Mr Barclay said.
