Mathis was born in Gilmer, Texas, on September 30, 1935, the fourth of seven children of Clem Mathis and Mildred Boyd. The family moved to San Francisco, California, settling on 32nd Avenue in the Richmond District, where Mathis grew up. His father had worked in vaudeville, and when he saw his son’s talent, he bought an old upright piano for $25 (US$363 in 2019 dollars) and encouraged him. Mathis began learning songs and routines from his father. His first song was “My Blue Heaven”. Mathis started singing and dancing for visitors at home, at school, and at church functions. Mathis is of African-American and Native American heritage.

Mathis was a star athlete at George Washington High School in San Francisco. He was a high jumper and hurdler, and he played on the basketball team. In 1954, he enrolled at San Francisco State College on an athletic scholarship, intending to become an English teacher and a physical education teacher. While there, Mathis set a high-jump record of 6′-5 1/2″ [1.97 m]. This is still one of the college’s top jump heights and was only 7 cm [two inches] short of the 1952 Olympic record of 2.04 m at the time. Just as when he was in high school, Mathis’s name was frequently mentioned in the sports sections of the Northern California newspapers. He and future NBA star Bill Russell were featured in a 1954 sports section article of the San Francisco Chronicle demonstrating their high-jumping skills (Russell #1 & Mathis #2 in the City of San Francisco at that time). During one meet at the University of Nevada, Mathis beat Russell’s highest jump attempt that day. Mathis was often referred to as “the best all-around athlete to come out of the San Francisco Bay Area.”

While singing at a Sunday afternoon jam session with a friend’s jazz sextet at the Black Hawk Club in San Francisco, Mathis attracted the attention of the club’s co-founder, Helen Noga. She became his music manager, and in September 1955, after Noga had found Mathis a job singing weekends at Ann Dee’s 440 Club, she learned that George Avakian, head of Popular Music A&R at Columbia Records, was on vacation near San Francisco. After repeated calls, Noga finally persuaded Avakian to come hear Mathis at the 440 Club. After hearing Mathis sing, Avakian sent his record company a telegram stating: “Have found phenomenal 19-year-old boy who could go all the way. Send blank contracts.”

At San Francisco State, Mathis had become noteworthy as a high jumper, and in 1956 he was asked to try out for the U.S. Olympic Team that would travel to Melbourne, Australia, that November. Mathis had to decide whether to go to the Olympic trials or to keep his appointment in New York City to make his first recordings. On his father’s advice, Mathis opted to embark on a professional singing career. His LP record album was released in late 1956 instead of waiting until the first quarter of 1957.

Mathis’s first record album, Johnny Mathis: A New Sound In Popular Song, was a slow-selling jazz album, but Mathis stayed in New York City to sing in nightclubs. His second album was produced by Columbia Records vice-president and record producer Mitch Miller, who helped to define the Mathis sound. Miller preferred that Mathis sing soft, romantic ballads, pairing him with conductor and music arranger Ray Conniff, and later, Ray Ellis, Glenn Osser, and Robert Mersey. In late 1956, Mathis recorded two of his most popular songs: “Wonderful! Wonderful!” and “It’s Not for Me to Say”. Also that year, Metro-Goldwyn-Mayer signed him up to sing the latter song in the movie Lizzie (1957).

His appearance on the popular TV program The Ed Sullivan Show in June 1957 helped increase his popularity. Later in 1957, he released “Chances Are”, which became his second single to sell a million. In November 1957, he released “Wild Is the Wind”, which featured in the film of the same name and was nominated for the Academy Award for Best Original Song. He performed the song at the ceremony in March 1958.

Later in 1958, Mathis made his second film appearance for 20th Century Fox, singing the song “A Certain Smile” in the film of that title. The song was also nominated for the Academy Award for Best Original Song.

Mathis appeared on ABC’s The Pat Boone Chevy Showroom on January 1, 1959.

Mathis had two of his biggest hits in 1962 and 1963, with “Gina” (number 6) and “What Will Mary Say” (number 9).

In October 1964, Mathis sued Noga to void their management arrangement, which Noga fought with a counterclaim in December 1964. Mathis purchased a mansion in Hollywood Hills, which was originally built by billionaire Howard Hughes in 1946, where he still maintains a residence.

After splitting from Noga, Mathis established Jon Mat Records, Inc., incorporated in California on May 11, 1967, to produce his recordings (previously, he founded Global Records, Inc. to produce his Mercury albums), and Rojon Productions, Inc., incorporated in California on September 30, 1964, to handle all of his concert, theater, showroom, and television appearances, and all promotional and charitable activities. His new manager and business partner was Ray Haughn, who, until his death in September 1984, helped guide Mathis’s career. Since that time, Mathis has taken sole responsibility for it.

In 1978, Mathis recorded “Too Much, Too Little, Too Late” with singer Deniece Williams. The lyrics and music were arranged by Nat Kipner and John McIntyre Vallins. Released as a single in 1978, it reached number one on the U.S. Billboard Hot 100 pop chart, number nine on the Canadian Singles Chart and number three on the UK Singles Chart. It also topped the US R&B and adult contemporary charts. “Too Much, Too Little, Too Late” was certified gold and silver in the US and in the UK by the RIAA and the British Phonographic Industry respectively. It was his first number one hit since his 1957 chart-topping “Chances Are”.

In 1978, his hit duet “The Last Time I Felt Like This” from the film Same Time, Next Year was nominated for an Academy Award for Best Original Song. Mathis and Jane Olivor sang the song at the Academy Awards ceremony, in his second performance at the Oscars. His first occurred 20 years earlier in 1958, when he sang “Wild Is the Wind” by Dimitri Tiomkin and Ned Washington from the movie of the same name. He was also awarded the Society of Singers Lifetime Achievement Award in 2006. In 2007, Mathis was inducted into the Hit Parade Hall of Fame. In 1988, Johnny appeared as a guest vocalist, accompanied by Henry Mancini, on Late Night with David Letterman to sing Henry’s theme to the “Viewer Mail” segment. In 2011, Mathis received the Golden Plate Award of the American Academy of Achievement presented by Awards Council member General Colin Powell.

Despite missing the Olympic high-jump trials, he retains enthusiasm for sports. He is an avid golfer, with nine holes in one to his credit. He has hosted several Johnny Mathis Golf Tournaments in the United Kingdom and the US. Since 1985, he has been hosting a charity golf tournament in Belfast sponsored by Shell corporation, and the annual Johnny Mathis Invitational Track & Field Meet has continued at San Francisco State University since it started in 1982. He also enjoys cooking and in 1982, he published a cookbook called Cooking for You Alone.

Mathis was quoted in a 1982 Us Magazine article, stating: “Homosexuality is a way of life that I’ve grown accustomed to.” Mathis later said that that comment was supposed to have been off the record and did not publicly discuss his sexual orientation for many years after that. In 2006, Mathis said that his silence had been because of death threats he received as a result of that 1982 article. On April 13, 2006, Mathis granted a podcast interview with The Strip in which he talked about the subject once again, and how some of his reluctance to speak on the subject was partially generational. During an interview with CBS News Sunday Morning on May 14, 2017, Mathis discussed the Us Magazine article and confirmed he is gay. “I come from San Francisco. It’s not unusual to be gay in San Francisco. I’ve had some girlfriends, some boyfriends, just like most people. But I never got married, for instance. I knew that I was gay.” Mathis spoke to many news sources, including CBS, about his sexuality and his story about coming out.

The week before his appearance at the Academy Awards, Johnny’s Greatest Hits was released. The album spent an unprecedented 490 consecutive weeks through 1967 (nine and a half years) on the Billboard top 200 album charts, including three weeks at number one. It held the record for the most number of weeks on the top Billboard 200 albums in the US for 15 years, until Pink Floyd’s The Dark Side of the Moon (March 1973) reached 491 weeks in October 1983.

The duo released a follow-up duet, “You’re All I Need to Get By,” peaking at number 47 on the Hot 100. The success of the duets with Williams prompted Mathis to record duets with a variety of partners, including Dionne Warwick, Natalie Cole, Gladys Knight, Jane Olivor, Stephanie Lawrence, and Nana Mouskouri. A compilation album also called Too Much, Too Little, Too Late, released by Sony Music in 1995 featured the title track among other songs by Mathis and Williams.

Mathis has been inducted into the Grammy Hall of Fame for three separate recordings – in 1998 for “Chances Are”, in 2002 for “Misty”, and in 2008 for “It’s Not for Me to Say”.

In 2003, the Academy of Recording Arts and Sciences awarded Mathis the Lifetime Achievement Award. This Special Merit Award is presented by vote of the Recording Academy’s National Trustees to performers who, during their lifetimes, have made creative contributions of outstanding artist significance to the field of recording.

Mathis returned to the British Top 30 album chart in 2007 with the Sony BMG release The Very Best of Johnny Mathis in 2008 with the CD “A Night to Remember” and again in 2011 with “The Ultimate Collection”

He has taped twelve of his own television specials and made over 300 television guest appearances, with 33 of them being on The Tonight Show. Longtime Tonight Show host Johnny Carson said, “Johnny Mathis is the best ballad singer in the world.” He appeared on the show with Carson’s successor, Jay Leno, on March 29, 2007, to sing “The Shadow of Your Smile” with the saxophonist Dave Koz. Through the years, his songs (or parts of them) have been heard in 100 plus television shows and films around the globe. His appearance on the Live by Request broadcast in May 1998 on the A&E Network had the largest television viewing audience of the series. Also in 1989, Johnny sang the theme for the ABC daytime soap opera Loving.

When he was 13, voice teacher Connie Cox accepted him as her student in exchange for work around her house. Mathis studied with Cox for six years, learning vocal scales and exercises, voice production, classical and operatic singing. The first band he sang with was formed by his high school friend Merl Saunders. Mathis eulogized Saunders at his funeral in 2008, thanking him for giving Mathis his first chance as a singer.

During 1980–81, Mathis recorded an album with Chic’s Bernard Edwards and Nile Rodgers, I Love My Lady, which remained unreleased in its entirety until its 2017 appearance in the 68 disc collection The Voice of Romance: The Columbia Original Album Collection. Three tracks had appeared on a Chic box set in 2010 and a fourth, the title track, on Mathis’ Ultimate Collection in 2011 and the Chic Organization’s Up All Night in 2013.

On June 21, 2014, Mathis was inducted into the Great American Songbook Hall Of Fame along with Linda Ronstadt, Shirley Jones, and Nat King Cole (whose daughter Natalie Cole accepted the award on his behalf). The awards were presented by the Center for the Performing Arts artistic director Michael Feinstein. Defined on their website, “Conceived as an enduring testament to the Great American Songbook, the Hall of Fame honors performers and composers responsible for creating America’s soundtrack.”

On January 14, 2016, Mathis performed to a sold-out audience in The Villages as part of his “60th Anniversary Concert Tour.”

In 2017, Mathis’s alma mater San Francisco State University awarded him an honorary Doctor of Fine Arts degree. Mathis attended San Francisco State for three semesters before withdrawing in 1956 to pursue his music career.