Nash developed an interest in photography as a child, and began to collect photographs in the early 1970s. He acquired more than a thousand prints by 1976. Between 1978 and 1984 an exhibition of selections from the Graham Nash Collection toured to more than a dozen museums world wide.
In 1990, Nash decided to sell his 2,000 print collection though Sotheby's auction house. It set an auction record for the highest grossing sale of a single private collection of photography.
In the early 1960s he was a leading member of The Hollies, one of the UK's most successful pop and "British Invasion" groups ever. Although a key member of the group, he seldom sang lead vocals, although he did write many of the band's songs, most often in collaboration with Allan Clarke.
Nash was pivotal in the forging of a sound and lyrics on The Hollies' albums. Nash was disappointed when his musical style did not catch on with the audience that were attracted to the Hollies, including when "King Midas in Reverse" did not do well. He played a key role in the direction of Evolution, and Butterfly, a collection that brought differing opinions on the band's musical direction of the group.
In 1968, after a visit to the US he met and spent time with David Crosby in Laurel Canyon. Nash left The Hollies and, beginning in 1972, teamed with Crosby and toured and recorded. Then Stephen Stills joined the duo. It became a more or less permanent combination by the time the CSN album was released in 1977.
Nash and Crosby reunited for another Crosby & Nash studio album in 2004, and a legitimate release of music from a 1970s Crosby-Nash tour as on a widely circulated bootleg appeared in 1998.
The Crosby, Stills & Nash threesome later became a foursome with Neil Young: Crosby, Stills, Nash & Young (CSNY). As part of this group, Nash went on to worldwide success and recognition of his musical talent.
Nash, nicknamed "Willy" by his band mates in CSNY, has been described as the glue that keeps their often fragile alliances together. A mark of this is the loyalty and support Nash showed to his best friend, Crosby, during Crosby's well-documented period of drug addiction ending in the mid 1980s.
Nash's has always been available for reunions on stage and in the studio with either Crosby and Stills or Crosby, Stills and Young. Nash also briefly rejoined the Hollies in 1983 to mark their 20th anniversary to record two albums, What Goes Around and Reunion.
His own solo work shows a love of melody and ballads. His solo recordings have experimented with jazz and electronic percussion but tend not to stray too far from a pop format with well-defined hook lines.
In 1979, Nash co-founded Musicians United for Safe Energy.
In 2005, Nash collaborated with Norwegian musicians a-ha on the songs "Over the Treetops" and "Cosy Prisons" for the Analogue recording.
In 2006, Nash worked with David Gilmour and David Crosby on the title track of David Gilmour's third solo album, On an Island. In March 2006, the album was released and quickly reached #1 on the UK charts.
Nash and Crosby subsequently toured the UK with Gilmour, singing backup on "On an Island," "The Blue," "Shine On You Crazy Diamond," and "Find the Cost of Freedom."
Nash is part of the No Nukes group which is against the expansion of nuclear power. In 2007 the group recorded a music video of a new version of the Buffalo Springfield song "For What It's Worth."
In 2010 Nash was inducted a second time to the Rock and Roll Hall of Fame, this time as a member of The Hollies.
He received an OBE 'for services to music and charitable activities', becoming an Officer of the British Empire in the Diplomatic and Overseas Division of the Queen's Birthday Honours List on Saturday, June 12, 2010. Nash received the title of George Eastman Honorary Scholar at the George Eastman House on January 22, 2011, in Rochester, NY.