The bike has been dubbed 'Holy Davidson' by auctioneers Bonhams.
A group in Austria called Jesus Bikers asked for the bike to be created and then given to the Pontifical Mission Societies to support Catholic missions overseas.
The money from the sale will go toward building an orphanage and a school for vulnerable children in Uganda.
After the bike was customised by Würzburg Village, it was presented to Pope Francis in a ceremony in St Peter's Square in July, where he signed it.
Bonhams said the bike has Mexican- American style detailing with a cross and the Pope's signature on the tank.
James Stensel, head of Bonhams Collectors' Motorcycles UK, said: "We are incredibly proud to be entrusted with the sale of this unique motorcycle, set to benefit such an important cause."
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