It will be the first time a female has officiated in a domestic twenty20 final.
"Both Kim and John are there 100% on their performances this season," New Zealand Cricket match officials manager Sheldon Eden-Whaitiri said.
"It's early in their careers, but getting to walk out for this final is a reward for their outstanding seasons so far."
For Cotton, who umpired at November's ICC Women's World T20 and was the first female TV umpire in a men's senior T20 match for last weekend's Canterbury-Central Districts game, the appointment is just another step in her swift rise in the the umpiring ranks.
"Kim makes good decisions and manages games well," Eden-Whaitiri said.
"Umpires are appointed by our selection panel, based on performance and player feedback - there's no gender differentiation for officials, it's the same for everyone.
"We'll see women umpiring men's first-class matches before long, 100%."
Cotton does not feel she has been under extra scrutiny because of her gender.
"The players test you the same as any other umpire - they're just interested in the right decisions, and that's what we want too," she said.
"We're all striving for that perfect game."
Wellington and Canterbury will contest the final. The game gets under way at 4pm, shortly after the men's game between Otago and Auckland.
- Otago suffered a big loss in its first match at the under-17 nationals in Lincoln yesterday.
Wellington posted 319 for six thanks largely to Tim Robinson, who scored 142 not out.
Otago was all out for 174 in reply to lose by 145 runs. Cameron Elliott top-scored with 51.
