"Roundabout" is a song by the English progressive rock band Yes from their fourth studio album Fragile, released in November 1971. It was written by singer Jon Anderson and guitarist Steve Howe and produced by the band and Eddy Offord. The song originated when the band were on tour and travelled from Aberdeen to Glasgow, and went through many roundabouts on the way.

The song was released as an edited single in the US in January 1972 with "Long Distance Runaround", another track from Fragile, as the B-side. It peaked at number 13 on the Billboard Hot 100 and number 10 on the Cash Box Top 100 singles charts. In 1973, Anderson and Howe won a BMI Award for writing the song.

The song originated in March 1971 when the band were on tour promoting The Yes Album (1971), travelling from Aberdeen to Glasgow after a gig in Aviemore, Scotland. They encountered many roundabouts on the way; Anderson claimed "maybe 40 or so", which inspired Anderson and Howe to write a song about the journey as they sat in the back of the band's transit van, and include the roundabouts and the surrounding mountains into the lyrics.

Anderson had smoked cannabis during the trip, "so everything was vivid and mystical". Anderson added: "It was a cloudy day, we couldn't see the top of the mountains. We could only see the clouds because it was sheer straight up ... I remember saying, 'Oh, the mountains–look! They're coming out of the sky!'" He began to write the song's lyrics in his notebook in a free-form style with minimal edits: "I just loved how words sounded when I put them together."

Within 24 hours, the band had arrived back home in London where Anderson reunited with his then wife Jennifer, which inspired the song's lyric "Twenty-four before my love, you'll see, I'll be there with you". A loch they passed as they neared Glasgow became the idea behind the line "In and around the lake". Upon their arrival at their hotel in Glasgow, Anderson and Howe began to put down song ideas on their recorder.

In August 1971, Yes regrouped in London to prepare material for their fourth album, Fragile (1971). Early into the sessions, keyboardist Tony Kaye was fired from the group over his lack of interest in learning more keyboards to expand the band's sound, and was replaced by Rick Wakeman. The group then moved to Advision Studios in September 1971 to record Fragile with audio engineer Eddy Offord as their co-producer, using a 16-track recording machine to layer their ideas, at which point, Howe later said, "The song became pure magic". The rhythm tracks were recorded first, in separate sections. Fragile contains four group-performed songs with five solo tracks written and arranged by each member; "Roundabout" is one of such collaborative tracks.

Howe recalled the track was originally "a guitar instrumental suite" and had a basic outline worked out when he first developed it. "All the ingredients are there—all that's missing is the song. "Roundabout" was a bit like that; there was a structure, a melody and a few lines." In 1994, former Yes guitarist Peter Banks whom Howe replaced in 1970, claimed he had come up with the song's main riff several years prior to the band recording it. The song was recorded in sections in a series of tape edits, a method of recording that was still relatively new to the group. They had played it through in rehearsal several times, but Squire recalled the group would make sure to "get the first two verses really good" and record from there.

In its original form, the song began with the acoustic guitar, which Howe played on a 1953 Martin 00–18, but the group soon thought a more dramatic opening was needed. This led to Wakeman playing an Em chord, alternating with a C chord on the piano that were recorded and played backwards, creating an effect that Howe described "as if it's rushing towards you". Offord recalled a considerable amount of time was spent to get it right in the studio because it involved a lengthy process of picking the right voicings to use, and editing them correctly. Howe thought the piano added a sense of drama, intensity, and colour to the song. An early idea had the song start with what Anderson described as "something of a Scottish jig" on Howe's acoustic guitar, which he had played to Anderson in their Glasgow hotel room.