The trio recorded "Look Into Your Heart" at Abbey Road studios, with Jagger on backing vocals and Wood on guitar, reported BBC.
It has been produced by Pink Floyd's Nick Mason and will raise funds for Save the Children's Nepal Earthquake appeal.
The single also features a choir of 100 of the charity's supporters, who won the opportunity in a charity auction.
"The terrible events in Nepal show just how vulnerable our fellow man can be in the face of nature," said lead vocalist Knight.
Wood said he was "delighted" to be able to help with the Nepal Appeal by featuring on the single, which is available to download on iTunes.