The Oscar-winner had been due to appear as the headline speaker at a charity lunch at Auckland's SkyCity on July 18, organised by The Simpatico Connection.
However, managing director Jacqueline Nagle today announced the event has been cancelled "due to issues within our organisation".
The statement did not shed any further light on those issues, instead apologising to Witherspoon and her fellow speakers.
"All ticket monies will be refunded. In the spirit of the event, The Simpatico Connection will make a donation to our charity partner SAVE THE CHILDREN," said Nagle.
Best known for her acting roles, from Legally Blonde through to 2014's Wild , Witherspoon is also an influential film producer.
She has also expanded into retail with her clothing and homeware line Draper James and philanthropy, including her longtime support for Save the Children.
Witherspoon is a mother of three, having had two children with first husband Ryan Phillippe and one with current spouse, Hollywood agent Jim Toth.
