James Bert Sonnier (born October 1, 1938 in Church Point, Louisiana) is a retired trainer of thoroughbred racehorses. A Cajun, at age eight he began galloping horses and learned about competitive racing at area bush tracks. In 1979, Bert Sonnier became the first trainer to saddle the winners of both the Arlington-Washington Futurity Stakes (Execution's Reason) and the Arlington-Washington Lassie Stakes (Sissy's Time) in the same year. Sonnier retired having won 1,531 races, saddling his last runner on February 10, 2003 at Gulfstream Park in Hallandale Beach, Florida.