"I Honestly Love You" was a worldwide pop hit single for Olivia Newton-John in 1974. The song was Newton-John's first number-one single in the United States and Canada, thus cementing her as a household name in North America. Released on the Long Live Lovealbum in the United Kingdom by EMI, it was eventually released on the album If You Love Me, Let Me Knowin the United States on MCA. The song was written by Jeff Barry and the Australian composer Peter Allen; the latter recorded it around the same time on his album Continental American. VH1 placed the song at #11 in the "40 Most Softsational Soft-Rock Songs" list.

The song topped the charts in the U.S. on October 5, 1974, and went on to sell over two million copies, being certified Platinum. It also reached number one (three weeks) on the Adult Contemporary charts and number six on the Country charts, and won Grammy Awards for Female Pop Vocal Performance and Record of the Year. The song's success also helped propel its parent album, If You Love Me, Let Me Know, to number one. Its title song was released as a single prior to "I Honestly Love You", and it was also a top-five multi-format (Pop - No. 5, Adult Contemporary - No. 2, and Country - No. 2) hit. By contrast, the single failed to reach the top-twenty in the United Kingdom (#22), although it did chart there in 1983 when it was re-released to promote a Newton-John greatest hits album.

Newton-John re-released the original hit version of the song in 1977, backed with "Don't Cry For Me Argentina" from her then-current album Making a Good Thing Better, and it reached number forty-eight Pop (outperforming the only single from Making A Good Thing Better, the title song, which stalled at number eighty-seven). The song also recharted on the Adult Contemporaries at No. 49.

This song also recharted on the Adult Contemporaries at No. 49. In 1998, she released a new version of "I Honestly Love You" from her album Back With a Heart, which featured Babyface on background vocals and reached number sixty-seven on the Billboard Hot 100, her first U.S. charted single in six years. The 1998 version also charted on the AC chart, No. 18, and in Country Music Sales, No. 16.

During the 1990s, this song was used in Australia to advertise tourism for Tasmania.

It was the first number one in the chart rundown to be shown on long-running Australian pop series Countdown.

The song is performed in the musical The Boy from Oz.

The song was covered by Bobby Vinton on his album Melodies of Love.

The song was performed regularly by the legendary Hong Kong singing icon Leslie Cheung.

Olivia Newton-John also reprised the song with her daughter Chloe Lattanzi on MTV, shortly after Chloe's notable turn on the VH-1 series "Rock the Cradle". The MTV version of the song was markedly different in terms of its significantly shorter duration, its instrumentalization relying on orchestral strings and deep bass notes, and its "dark" tone, in stark contrast to the original, which was a "bubble-gum" pop love ballad. In the performance, Chloe donned a so-caller "provocative" outfit and sang the first verse before being joined by her mother for the chorus. Newton-John sat on a throne during the performance with her daughter beside her.

The song was briefly mentioned in the 2001 film The Wedding Planner, which starred Jennifer Lopez and Matthew McConaughey. Lopez's character Mary mentions that any couple who chooses the song for their wedding song is doomed to divorce in under a year.

"Nel blu dipinto di blu (Volare)" · "Mack the Knife" · "Theme from A Summer Place" · "Moon River" · "I Left My Heart in San Francisco" · "Days of Wine and Roses" · "The Girl from Ipanema" · "A Taste of Honey" · "Strangers in the Night" · "Up, Up and Away" · "Mrs. Robinson"

"Aquarius/Let the Sunshine In" · "Bridge over Troubled Water" · "It's Too Late" · "The First Time Ever I Saw Your Face" · "Killing Me Softly with His Song" · " I Honestly Love You " · "Love Will Keep Us Together" · "This Masquerade" · "Hotel California" · "Just the Way You Are"

"What a Fool Believes" · "Sailing" · "Bette Davis Eyes" · "Rosanna" · "Beat It" · "What's Love Got to Do with It" · "We Are the World" · "Higher Love" · "Graceland" · "Don't Worry, Be Happy"

"Wind Beneath My Wings" · "Another Day in Paradise" · "Unforgettable" · "Tears in Heaven" · "I Will Always Love You" · "All I Wanna Do" · "Kiss from a Rose" · "Change the World" · "Sunny Came Home" · "My Heart Will Go On"

"Smooth" · "Beautiful Day" · "Walk On" · "Don't Know Why" · "Clocks" · "Here We Go Again" · "Boulevard of Broken Dreams" · "Not Ready to Make Nice" · "Rehab" · "Please Read the Letter"

"Use Somebody"