About 80 gathered in the city to celebrate the 150th anniversary of their ancestors' arrival at Dunedin from Scotland in 1863.
Descendants from throughout New Zealand were joined by those living in Australia, England and Argentina.
Clan Donald Queensland commissioner Suzanne MacDonell-Lambkin said her family traits were partly responsible for her involvement in the clan gathering.
''It was only by chance that I heard from another lady who's related on the other side of the family that this was even on. From there, the Celtic spirit kicked in and I refused to give up in finding where my ancestors fitted in. The stubborn MacDonell kicked in,'' she said.
Mrs MacDonell-Lambkin said she was the only great-great-great-great granddaughter of Roderick MacDonell, who followed his siblings Catherine Jackson (nee MacDonell) and Lachlan MacDonell to Dunedin and then settled in Victoria, Australia.
Clan MacDonell of Glengarry was a branch of the larger Clan Donald, and many clan members settled in Otago, where they raised large families.
Reunion co-organiser Heather McLay, of Blenheim, said it was lovely to return to Dunedin, where she grew up.
Mrs McLay started researching her ancestry in 2008, which put her in contact with other MacDonell descendants.
The idea of a clan gathering in Dunedin ''grew from that'' and organisation for the 150th anniversary reunion started early this year.
Mrs McLay said it had been a wonderful weekend and descendants had enjoyed meeting one another.
Half of them toured the wider Dunedin area yesterday, visiting graves of key clan members, including the MacDonell chief buried in the Southern Cemetery.
Among those involved in the reunion was former Dunedin Labour MP Brian MacDonell, now of Tasmania, as well as Clan Donald New Zealand commissioner Harold McIsaac and Otago president Wendy Hellyer.