The two got married on New Year's Day in Puerto Rico.
According to Twain's website, 40 close relatives and friends watched the couple tie the knot.
Twain and Thiebaud announced their engagement in December.
The two got together after Twain's now ex-husband allegedly had an affair with Thiebaud's now ex-wife.
The 45-year-old singer from Ontario, Canada, said she reached out to Frederic Thiebaud in the aftermath, writing on her website last year that she had found "a dear friend and true gentleman."
Twain has an autobiography due out in the spring and is scheduled to have her own show on Oprah Winfrey's television network.
The Associated Press contributed to this report.