The couple got married last month in a small ceremony in Las Vegas, but threw a formal event for friends and family on Saturday, People magazine reports.
The wedding took place at a chateau amid record-breaking temperatures, following a rehearsal dinner in Provence the previous evening.
Turner and Jonas revealed they were dating in January 2017, after they were spotted kissing at a Kings of Leon concert in the Netherlands.
They announced their engagement on Instagram in October that year.
Although they wanted a European wedding, they had to make it official in the US first, so married on 1 May in a surprise Las Vegas ceremony officiated by an Elvis impersonator after the Billboard Music Awards.
“We had to do a legal marriage before we did a real big one,“ Jonas told Harper's Bazaar.
”It was either the courthouse or our version, and I preferred our version: friends, Elvis and Ring Pops.”
The wedding was supposed to be a secret, but DJ Diplo live streamed the ceremony on Instagram to his 5 million followers.
Jonas, 29, recently released a Jonas Brothers reunion album, “Happiness Begins”, while 23-year-old Turner has just wrapped up the final season of Game of Thrones, in which she played Sansa Stark.
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