"The Sounds of Silence" is the song that propelled the 1960s folk music duo Simon and Garfunkel to popularity. It was written in February 1964 by Paul Simon in the aftermath of the November 22, 1963 assassination of U.S. President John F. Kennedy.

The song features Simon on acoustic guitar and both Simon and Garfunkel singing. It was originally recorded as an acoustic piece for their first album Wednesday Morning, 3 A.M.but on the initiative of the record company was later overdubbed with electric instruments and rereleased as a single in September 1965. The single reached number one on New Year's Day 1966 and was included in the 1966 album Sounds of Silence.

The song was originally called "The Soundsof Silence" and is titled that way on the early albums in which it appeared and on the single. In later compilations it was retitled "The Sound of Silence". Both the singular and the plural form of the word appear in the lyrics. In his book Lyrics 1964–2008Simon has the title in the singular.

Simon began working on the song sometime after the Kennedy assassination. He had made progress on the music but had yet to get down the lyrics. On 19 February 1964 the lyrics apparently coalesced, and Simon showed the new composition to Garfunkel the same day. Shortly afterward, the duo began to perform it at folk clubs in New York. They recorded it for the first time on March 10, and included the track on their debut album, Wednesday Morning, 3 A.M., released that October. The album flopped upon its release, and the duo split up, with Simon going to England for much of 1965. There he often performed the song solo in folk clubs, and recorded it for a second time on his solo LP in May 1965, The Paul Simon Songbook.

In the meantime, Simon and Garfunkel's producer at Columbia Records in New York, Tom Wilson, had learned that the song had begun to receive airplay on radio stations in Boston, Massachusetts and around Gainesville and Cocoa Beach, Florida.

On June 15, 1965, immediately after the recording session of Bob Dylan's "Like a Rolling Stone," Wilson took the original track of Simon & Garfunkel, and overdubbed the recording with electric guitar (played by Al Gorgoni), electric bass (Bob Bushnell), and drums (Bobby Gregg), and released it as a single without even consulting Simon or Garfunkel. For the B-Side Wilson used an unreleased track he cut with the duo a few months earlier on which they had tried out a more "contemporary" sound. "Sounds of Silence"/"We've Got a Groovey Thing Going" entered the U.S. pop charts in September 1965 and slowly began its ascent.

Simon learned that it had entered the charts minutes before he went on stage to perform at a club in Copenhagen, Denmark, and in the later fall of 1965 he returned to the United States. By the end of 1965 and the first few weeks of 1966, the song reached number one on the U.S. charts. Simon and Garfunkel then reunited as a musical act, and included the song as the title track of their next album, Sounds of Silence, hastily recorded in December 1965 and released in January 1966 to capitalize on their success. The song propelled them to stardom and, together with two other top-five (in the U.S.) hits in the summer of 1966, "I Am a Rock" and "Homeward Bound," ensured the duo's fame. In 1999, BMI named "The Sounds of Silence" as the 18th-most performed song of the 20th century. In 2004 it was ranked #156 on Rolling Stone's list of the 500 Greatest Songs of All Time, one of the duo's three songs on the list.

The original acoustic stereo mix of the song had the duo's vocals on separate channels, spotlighting the delicate harmonies. When the 'rock' version was mixed to stereo, Wilson mixed the vocals in the middle, which is not as clear sounding as the original acoustic version.

On the duo's 1968 album Bookends, the track "Save the Life of My Child" features a distorted sample of Art Garfunkel's " Hello darkness my old friend, I've come to talk with you" line from the original recording of "The Sounds Of Silence"). At 2:16 in the song somebody says "echo me"

In 2009, the song was released (along with "I Am a Rock") as a downloadable track for rhythm video game Rock Band 2

"The Sounds of Silence" was released on Columbia Records as 45 rpm catalog number #4-43396. The single has several variations:

The song was used three times in the film The Graduate, played during the opening credits and the closing footage, and in the film Bobby, where it is played during Robert Kennedy's victory speech at the Ambassador Hotel, just before his assassination. It can also be heard in the last episodes of the Japanese dorama Taiyo to Umi no Kyoshitsu. It can also be heard in the comedy film Old Schoolwhen Will Ferrell gets shot with a tranquilizer dart and falls into the pool going into a dream daze. Additionally, the song is played in the film Kingpin, following sexual activity between protagonist Roy Munson and his landlady. In the film More American Graffiti, the 1966 recording is heard playing after a rather large bar fight. In 2009's Watchmenthe song is featured on the soundtrack for the film and used during The Comedian's funeral.