Organising committee chairwoman Tricia Batkin, of Cambrian, near St Bathans, said informing people about their family history was the highlight of the event.
William Driver left Yorkshire, in the United Kingdom, in 1852 for Australia, married Mary Ann Challis there, and the couple arrived at Port Chalmers in 1861.
Mr Driver worked as a tailor in George St, Canongate and Dowling St, and the couple had eight children.
Ms Batkin said family members, all keen genealogists, got together last year, and decided on a bigger reunion this year.
Among other activities, the group unveiled a plaque in the Northern Cemetery on the couple's previously unmarked grave.
"They were just good, honest, hard-working people. They were not high flyers," she said.
While most of the descendants who attended were from south of Christchurch, some were from Auckland and South Australia.