Lynn grew up in Kansas City, Missouri. When she was 17, she auditioned for the United Service Organizations and ended up touring with the USO tour in the China Burma India Theater the following year. She would sing requested songs for recently released prisoners of war, showing off her mezzo-soprano pipes in order to cheer up the troops.
When she returned to the United States, Lynn got her big break appearing in numerous Broadway productions like Oklahoma! and Park Avenue which led to a contract deal with Hollywood. Starting in the late 40s, Lynn started appearing in multiple major films including Sitting Pretty, June Bride with Bette Davis, Cheaper by the Dozen, Mother Is a Freshman and Payment on Demand. She also appeared in guest roles in multiple TV shows like Schlitz Playhouse of Stars and The Gale Storm Show.
In an interview with Artist Chronicle, Lynn explained that initially, it really wasn't a set plan to give Barney Fife his own love interest. At the time she first appeared on the popular sitcom in the episode "Cyrano Andy," she was actually under contract with the series Texas John Slaughter. But after that show was canceled, Andy Griffith kept bringing her back occasionally and the love story just seemed to unfold on its own.
"I didn't have any contract," Lynn explained. "They called me in occasionally, and I got to play opposite Don Knotts, who I loved."
Though Lynn only appeared in 26 episodes, her character was a big part of the show, especially for Deputy Fife. The only reason her character was even cut from the show was due to Knotts' decision to leave the series. But she did come back for Return to Mayberry where fans finally got to see Barney and Thelma tie the knot. Lynn hasn't appeared in any acting roles since the 80s, her final appearance being opposite her former co-star Andy Griffith in an episode of his TV series Matlock.
Despite her other acting roles, The Andy Griffith Show was always an incredibly important experience to Lynn. In fact, she regularly appeared at the Andy Griffith Museum in Mount Airy, North Carolina to sign autographs for fans.
Ron Howard, who famously portrayed Opie on The Andy Griffith Show, honored his former co-star on social media.
"I saw her last a few years ago where she still lit up the room with her positivity," Howard wrote. "It was great to have known and worked with her."
RIP Betty Lynn. She played Thelma Lou on #TAGS & brightened every scene she was in & every shooting day she was on set. I saw her last a few years ago where she still lit up the room with her positivity. It was great to have known and worked with her. She truly was 95yrs young. https://t.co/2KMMQRz4PP
— Ron Howard (@RealRonHoward) October 17, 2021