Welsh was to have come to the city in September for a Dunedin Writers and Readers Festival event.
But festival programme director Claire Finlayson confirmed today he was not able to come, as the date clashed with a family funeral he had to attend in the United Kingdom.
Ms Finlayson said she hoped he would be able to come at a later date.
Born in 1958, the Scottish novelist is best known for Trainspotting, later made into a 1996 film of the same name.
A film sequel, T2 Trainspotting, was released last year.