The album era (sometimes, album-rock era) was a period in popular music, usually defined as the mid-1960s through the middle of the 2000s decade, in which the album—a collection of songs issued on physical media—was the dominant form of recorded music expression and consumption. It was driven primarily by three storage formats: the 33⅓ rpm long-playing record (LP), the cassette tape, and the compact disc (CD). Rock musicians from the United States and the United Kingdom were often at the forefront of the era. The term "album era" is also used to refer to the marketing and aesthetic period surrounding a recording artist's release of an album.

Long-playing record albums, first released in 1948, offered the ability to sell larger amounts of music than singles. The album era arrived in earnest in the mid-1960s, when the Beatles began to release artistically ambitious and top-selling LPs. The industry embraced albums to immense success, and burgeoning rock criticism validated their cultural value. By the 1970s, the LP had emerged as a fundamental artistic unit and a widely popular item with young people. Some were concept albums, especially by progressive musicians in rock and soul.

As the 1970s became the 1980s, sales of LPs declined, thanks to the advent of the singles-oriented genres of punk rock and disco and the advent of music videos on MTV. This threatened the profits of music companies, which responded over the next decades by releasing fewer singles and by raising the prices of albums released in the popular new CD format. The success of major pop stars led to the development of an extended rollout model among record labels: marketing an album around a catchy lead single, an attention-grabbing music video, novel merchandise, media coverage, and a supporting concert tour. Women and black musicians continued to gain critical recognition among the album era's predominantly white-male and rock-oriented canon, with the burgeoning hip hop genre developing its own album-based standards. In the 1990s, the music industry saw an alternative rock and country music boom, leading to a revenue peak of $15 billion in 1999 (based on CD sales).

The rise of the Internet began to undermine the album. First, file sharing networks such as Napster enabled consumers to illegally rip and share their favorite tracks from CDs. In the early 21st century, music downloading and streaming services emerged as premier means of distributing music, album sales suffered a steep decline, and recording acts generally focused on singles, effectively ending the album era.

Technological developments in the early 20th century led to sweeping changes in the way recorded music was made and sold. Before the LP, the standard medium for recorded music had been the 78 rpm gramophone record, made from shellac and holding three to five minutes per side. The capacity limitations constrained the composing processes of recording artists, while the fragility of shellac prompted the packaging of these records in empty booklets resembling photo albums, with typically brown-colored wrapping paper as covers. The introduction of polyvinyl chloride in record production led to vinyl records, which played with less noise and more durability.

In the 1940s the market for commercial- and home-use recordings was dominated by the competing RCA Victor and Columbia Records, whose chief engineer Peter Carl Goldmark pioneered the development of the 12-inch long play (LP) vinyl record. This format could hold recordings as long as 52 minutes, or 26 minutes per side, at a speed of 33⅓ rpm, and was playable with a small-tipped "microgroove" stylus designed for home playback systems. Introduced in 1948 by Columbia, LPs became known as "record albums", termed in reference to the photo album-like 78 packaging. Another innovation from Columbia was the addition of graphic and typographic design to album jacket covers, introduced by Alex Steinweiss, the label's art director. Encouraged by its positive effect on LP sales, the music industry adopted illustrated album covers as a standard by the 1950s.

Originally the album was primarily marketed for classical music listeners, and the first LP released was Mendelssohn: Concerto in E Minor for Violin and Orchestra Op. 64 (1948) by Nathan Milstein and the Philharmonic-Symphony Orchestra of New York under Bruno Walter. Film soundtracks, Broadway show cast recordings, jazz musicians, and some pop singers such as Frank Sinatra soon used the new longer format. Jazz artists especially, such as Duke Ellington, Miles Davis, and Dave Brubeck, preferred the LP because it allowed them to record their compositions with concert-length arrangements and improvisations. The original Broadway cast recording of the musical Kiss Me, Kate (1949) sold 100,000 copies in its first month of release and, together with South Pacific (which topped the album charts for 63 weeks), brought more attention to LPs, while the Broadway cast recording of My Fair Lady became the first LP to sell one million copies. However, in the 1950s and into the 1960s, 45 rpm seven-inch single sales were still considered the primary market for the music industry, and albums remained a secondary market. The careers of notable rock and roll performers such as Elvis Presley were driven primarily by single sales.

The arrival of the Beatles in the U.S. in 1964 is credited by music writers Ann Powers and Joel Whitburn as heralding the "classic album era" or "rock album era". In his Concise Dictionary of Popular Culture, Marcel Danesi comments that "the album became a key aspect of the countercultural movement of the 1960s, with its musical, aesthetic, and political themes. From this, the 'concept album' emerged, with the era being called the 'album era'". According to media academic Roy Shuker, with the development of the concept album in the 1960s, "the album changed from a collection of heterogeneous songs into a narrative work with a single theme, in which individual songs segue into one another", "unified by a theme, which can be instrumental, compositional, narrative, or lyrical".