Donald Richard "Don" Spencer OAM (born 22 March 1941)  , is an Australian children's television presenter, singer-songwriter, guitarist and musician. He had a long-running role on Play School on both the Australian version (1968–99) and the United Kingdom version (1972–88), the only presenter to work on both versions. In March 1963 his first single, "Fireball" – the theme tune to a UK TV science fiction series, Fireball XL5 – reached No. 32 on the UK Singles Chart. In 2002 Spencer established the Australian Children's Music Foundation. On Australia Day (26 January) 2007 he was awarded a Medal of the Order of Australia (OAM) with the citation "for service to children's music and television as a songwriter and performer, and through the establishment of the Australian Children's Music Foundation". Spencer married Julie Horsfall, they have two children: Dean, a musician; and Danielle Spencer, an actress and singer, who married actor Russell Crowe in 2003.
Donald Richard Spencer was born on 22 March 1941 and raised in Tamworth.  Spencer attended Tamworth High School,  he played hockey as a teenager and competed in the Australian championships. At 17 he left Australia and travelled to Africa where, in his 20s, he trained with the Kenyan hockey team trying out for the Olympics. A chance meeting with locally-born, singer-songwriter, Roger Whittaker, in Nairobi inspired Spencer to buy a guitar and start his musical career.
In the early 1960s Don Spencer moved to London and became a solo singer-guitarist, supporting various acts as The Rolling Stones, the Four Seasons, The Hollies and Marianne Faithfull.  His first single, "Fireball", was released on the His Master's Voice label – it was the closing theme song for the television science fiction series, Fireball XL5 , written by Barry Gray. In March 1963 it reached No. 32 on the UK Singles Chart.   Other singles included "Busy Doing Nothing", "Worried Mind", "Marriage Is for Old Folks", and a cover of The Beatles' song "In My Life". In 1964 he covered Brent Edwards version of Johnny Madara and David White's track, "Pride Is Such a Little Word". 
Spencer presented his own teenage pop show, Gangway! , for seven years, then co-hosted Pop-In .  He later appeared in TV comedies, Face It with Ronnie Barker . Returning to Australia, he appeared on TV's Bandstand , and acted in Sons and Daughters , Return to Eden , and in the 1974 film Barry McKenzie Holds His Own .  In 1977 Spencer wrote his next single, "What's a Pommie?", the track was covered by fellow Australians Rolf Harris, and Col Elliott. 
In 1968 Spencer became a presenter on Australia children's TV series, Play School , in 1972 he also appeared on the United Kingdom version of the same title.   He continued on both versions for 17 years,  the only male presenter to appear in both. One of his well-known phrases was "old magazines" which he used to effect when describing items used to make something.  During this period he recorded and released albums that helped to educate children mostly about the many species of Australian animals, and they in turn had received awards for gold and platinum sales.   He continued on the Australian version until 1999.  At the APRA Music Awards of 1995, Spencer's track, "Have a Beaut Day", was nominated for Most Performed Children's Work; it was co-written by Spencer with Allan Caswell. 
In 2002 Spencer established the Australian Children's Music Foundation (ACMF) as its inaugural CEO.   In 2007 he was awarded a Medal of the Order of Australia (OAM) on Australia Day (26 January) for "service to children's music and television as a songwriter and performer, and through the establishment of the Australian Children's Music Foundation".    In 2008 Spencer was awarded for Excellence in Community Support presented by Support Act Limited.  
In December 2010 the ACMF sponsored a supergroup, Peacebeliever, which recorded a cover version of Plastic Ono Band's 1969 single, " Give Peace a Chance ", for the charity.  Alongside Spencer fellow vocalists were Katie Noonan, Blue King Brown, Tim Freedman, Newton Faulkner and Omara Portuondo.  In July 2013 Spencer announced the ACMF's 11th annual National Kids Songwriting Competition, which is open to school aged children from four to eighteen years-old: "We want kids to unleash their creativity and engage with learning in a fun way ... Music can give kids really positive self expression and is a great tool for improving literacy levels". 
Don Spencer married Julie Horsfall, a caterer from Yorkshire.  They have two children Dean and Danielle Spencer (born 16 May 1969).  Dean is a musician, while Danielle is an actress and singer, who married actor, Russell Crowe, in 2003.