Yacht rock (originally known as the West Coast sound or adult-oriented rock) is a broad music style and aesthetic commonly associated with soft rock, one of the most commercially successful genres from the mid-1970s to the mid-1980s. Drawing on sources such as smooth soul, smooth jazz, R&B, and disco, common stylistic traits include high-quality production, clean vocals, and a focus on light, catchy melodies. The term yacht rock was coined in 2005 by the makers of the online comedy video series Yacht Rock, who connected the music with the popular Southern Californian leisure activity of boating. It was considered a pejorative term by some music critics.

The term yacht rock did not exist contemporaneously with the music the term describes, which was produced from 1975 to 1984. It refers to "adult-oriented rock" or the "West Coast Sound", which became identified with yacht rock in 2005, when the term was coined in J. D. Ryznar et al.'s online video series of the same name. Many "yacht rockers" included nautical references in their lyrics, videos, and album artwork, exemplified by Christopher Cross's anthemic track, "Sailing" (1979). Long mocked for "its saccharine sincerity and garish fashion", the original stigma attached to the music has lessened since about 2015.

In 2014, AllMusic's Matt Colier identified the "key defining rules of the genre:"

The "exhilaration of escape" is "essential to yacht", according to journalist and documentary filmmaker Katie Puckrik. She quoted the lyrics of Cross's "Ride Like the Wind" (1979), "to make it to the border of Mexico", as an example of the aspirational longing that demonstrates "the power of the genre". Thwarted desire is another key element that counters the "feelgood bounce" of yacht in the same song. Puckrik identified a sub-genre, "dark yacht", exemplified in Joni Mitchell's "accidental yacht rock" song "The Hissing of Summer Lawns" (1975), which described the "tarnished love" of "a woman trapped in a big house and a loveless marriage".

According to Mara Schwartz Kuge, who worked in the L.A. music industry for two decades, "Soft rock was a genre of very popular pop music from the 1970s and early 1980s, characterized by soft, mostly acoustic guitars and slow-to-mid tempos ... most people have generalized the term to mean anything kind of soft-and-1970s-ish, including artists like Rupert Holmes. Not all yacht rock is soft, either: Toto's 'Hold the Line' and Kenny Loggins' 'Footloose' are both very yacht rock but not soft rock."

Comprehensively defining yacht rock remains difficult, despite agreement that its central elements are "aspirational but not luxurious, jaunty but lonely, pained but polished". Journalist Jack Seale stated that, as in other "micro-genres", certain albums of artists who are accepted as proponents are "arbitrarily ruled in or out". For example, Michael Jackson's Thriller (1982) is accepted as yacht rock, but Fleetwood Mac's Rumours (1977) is not.

Yacht Rock web series co-creators Ryznar, Steve Huey, Hunter Stair, and David Lyons have attempted to apply precision to what is defined as yacht rock, and have been critical of overly expansive definitions of the term. In 2016, they invented the term "nyacht rock" to refer to songs that have sometimes been classified as yacht rock but that they felt did not fit the definition. On their podcasts Beyond Yacht Rock and Yacht or Nyacht?, they have categorized various songs as being either within or outside of the genre.

Factors that the four list as relevant to yacht rock include: