Cathryn Antoinette "Toni" Tennille is an American singer-songwriter and keyboardist, best known as one-half of the 1970s duo Captain & Tennille with her former husband Daryl Dragon; their signature song is "Love Will Keep Us Together". Tennille has also done some musical work independently of her husband, including solo albums and session work.

While living in Corona del Mar in Newport Beach, California, during the late 1960s, Tennille was a member of the South Coast Repertory. Ron Thronsen, one of the directors of the repertory, asked Tennille in 1969 to write the music for a new rock musical he was working on called Mother Earth. The musical was a success locally, went on the road to San Francisco and Los Angeles in 1971, and eventually made it to Broadway for a few dates at the Belasco Theatre in October 1972. Although Tennille was no longer associated with the musical by the time it reached Broadway, she was credited as the composer under her married name, Shearer.

In 1971, Tennille met her future husband Daryl Dragon in San Francisco during auditions for Mother Earth. Dragon had previously toured with the Beach Boys and had recorded with them as a studio musician. After Mother Earth ended, Dragon returned to the Beach Boys and introduced Tennille to the band.[8] Tennille played electric piano with the band during their 1972 tour. In 1973, Tennille and Dragon left to form Captain & Tennille and began performing at local clubs. In September 1973, they released their self-financed debut single, "The Way I Want to Touch You", which was a local hit and helped them to get a record contract with A&M Records. The duo recorded a cover version of the Neil Sedaka and Howard Greenfield song "Love Will Keep Us Together" in 1975 that became a huge success and eventually went on to win the 1975 Grammy Award for Record of the Year.

In 1974, Tennille sang background vocals on Elton John's Caribou album. In 1979, she sang backing vocals on Pink Floyd's The Wall. Following a December 1979 pilot, from September 1980 to February 1981 Tennille hosted her own syndicated television talk show, The Toni Tennille Show. From September 1998 to June 1999, Tennille performed as "Victoria Grant/Count Victor Grazinski" in the national tour of the play Victor Victoria.

With her then husband Daryl Dragon, as Captain & Tennille, she recorded the Christmas song "Saving Up Christmas" included in their DVD box set for 1976-1977's The Captain & Tennille Show; this was followed by a full-length Christmas album titled The Secret of Christmas, released in 2007.

In April 2016, Tennille released her memoir, Toni Tennille: A Memoir, and went on a book tour to promote it later that summer.[18][19] An audiobook of the memoir was also released on the audiobook service Audible.