Elton has sent a personal get well soon message to four-year-old Lily-Mae Morrison.
As reportedly previously, the four-year-old, who is from Galway, has been diagnosed with high risk neuroblastoma.
Over 300 performers collaborated on a cover of Elton's old hit, Tiny Dancer, which was released to raise money for the Sunni-Mae Trust and the Neuroblastoma Society. The participants included Paddy Casey, Mary Black, Declan O'Rourke and Camille O'Sullivan.
Elton, who was recently in Hong Kong, recorded the message while on tour and sent it to Lily-Mae's parents Leighton and Judith.
Leighton said he was "delighted" at Elton's support.
Bernie Taupin has also backed the release of the single.