Arthur-Hay was born Antoinette Alice Priscilla Wilson in Oxford, England. She describes her childhood as 'lovely, working class, dead ordinary'. At the age of nine, she won a scholarship to the Royal Academy of Music, and gave a concert at the Wigmore Hall in the same year. She was educated at Mary Datchelor Girls School in Camberwell and the Royal Academy of Music.
In the 1959 Toni Arthur went to University College Hospital to become a nurse, and then went on to start a degree in Psychology at UCL.
Arthur is most popularly remembered as one of the presenters of the children's programmes Play School and Play Away alongside Brian Cant and Lionel Morton. She also presented Woman's Hour, TV-am's breakfast show and many other programmes.
In 2010, Toni criticised modern children's TV programmes and called for gentler programmes to allow toddlers to build up reassuring relationships with presenters.
Toni Arthur met her first husband Dave Arthur in 1964, and they decided to become folk singers,She released several folk music albums in the late 1960s and early 1970s with her husband, Dave Arthur. These included Morning Stands on Tiptoe (1967), The Lark in the Morning (1969) and Hearken to the Witches Rune (1971). Toni says that she and Dave Arthur travelled the world, singing in folk clubs.
'Hearken to the Witches Rune' was released on the red Trailer label in the UK in 1971. The tracklist was as follows: Alison Gross, Tam Lin, A Fairy Tale,The Fairy Child, Broomfield Hill, The Standing Stones, The Cruel Mother, and Alice Brand. All are traditional songs. Some copies of this album came with a 'Magic In Ballads' booklet.
Toni claims that it was while she was in a folk club that a BBC producer approached her about auditioning for a children's BBC programme called 'Playschool.' She got the job, even though, she says she was wearing 'an incredibly short skirt.' 
Toni Arthur also appeared on a BBC album that was a spin off from the BBC children's programme 'Play Away' in 1977. 'Ready Steady Go Play Away' was full of songs in the Music Hall style. Toni appeared as a solo artist on tracks such as 'Doctor Foster Tours The World', 'Running, Stretching, Racing', 'Why Does The Winkle Always Turn To The Right?' and 'Night Express North Bound'. She also performed many ensemble songs with Brian Cant, while Jonathan Cohen, Spike Heatley and Alan Rushton (who had all played at Ronnie Scott's) formed a tight band. Brian and Toni weave a 'night on the town' narrative in and out of the songs about Music Hall, coffee bars and gambling. The back cover of the album sleeve also featured a board game.
Arthur has written several plays and books, including 'All The Year Round - A Compendium of Games, Customs and Stories', which was a children's book of crafts for celebrating the seasons. This was published by Puffin Books on 27st August 1981, ISBN 0140313206.
In 2000, Toni Arthur appeared on a programme called Mystic Challenge, and spoke out her relationship with Buddhism. 'I started reading about Buddhism, and found that that philosophy of knowing yourself before you know others, suited me, and I have been a Buddhist ever since.'