KYLIE Gray has been elected mayor of Yorke Peninsula Council after securing a decisive victory in the supplementary election.

Ms Gray received 2615 votes, or 72.42 per cent of the 3611 formal ballots cast.

Her opponent, Michael O'Connell, recorded 996 votes (27.58 per cent).

The election was triggered by the resignation of former mayor Darren Braund in May. Councillor Richard Carruthers had been serving as acting mayor in the interim.

Voting was conducted entirely by post, with ballots due by noon on Monday, September 22. The count was held the following day, and Ms Gray was provisionally declared elected mid-afternoon after passing the quota of 1806 votes.

The Electoral Commission of South Australia ran the election and oversaw the count.

Of the 9461 eligible voters, 3685 (38.95 per cent) returned declaration envelopes containing ballot papers. Fifty-nine envelopes were rejected or excluded, giving a participation rate of 38.33 per cent. Of the 3627 accepted envelopes, 15 contained informal votes.