Newcomer Brendan Kelly has unseated Black Diamond's outgoing mayor, Ruth Goodwin.
Kelly was voted in with 565 votes to Goodwin's 308 votes.
Goodwin, a longtime council member turned mayor, was seeking her second term as mayor going into a likely amalgamation with Turner Valley.
Kelly, a school teacher at Eden Valley's Chief Jacob Bearspaw School, campaigned on improved communication, including more use of social media to keep residents informed.
He also ran on a platform of supporting small businesses.
He told the Western Wheel he was encouraged to run for mayor by some current Black Diamond councillors and local residents and business owners.
This story will be updated.