"She has been brilliant, that's why she's been chosen," said Mrs Patterson.
"There were some awesome applications, which highlight the number of people who volunteer and do amazing work in the community."
The other finalists up for the award were Sam Milligan, Evelyn Skeet and Maureen Potts, all from Masterton, Elizabeth Hubbard from Carterton, and Stan Mangin from Greytown.
Former Masterton mayor and patron of Age Concern Wairarapa WOOPS Bob Francis presented the award to Mrs Underhill at the Ageing with Attitude Expo 2015, held yesterday at the Genesis Recreation Centre.
Mrs Underhill said she felt "very humbled" to receive the award.
"I enjoy doing what I do," she said.
"It's the pleasure you get out of giving - by giving, you're receiving."
Mrs Underhill assists with the South End School reading programme.
She prepares and delivers food to elderly people, those who are sick and to families who have suffered a loss.
In earlier years, she managed wardrobe for the New Zealand Ballet and is a registered nurse.
"When I retired, the community became my challenge," she said.
Mrs Underhill raised $5000 for the Carterton Event Centre through selling her homemade jam.
When the Carterton balloon accident happened, Mrs Underhill cooked everything she had in her fridge, piled the food into the boot of her car and took it to the crash scene for the emergency workers.
"I couldn't help the victims but I could feed the people there helping them."
She said you had to use your eyes and ears to spot where there was a need.
Mrs Underhill is president of the Carterton District Historical Society and a member of the Iris Society.
"The garden's got plenty of weeds in it but the kids down the road aren't starving," she said.
Age Concern programme co-ordinator Annette Peters said they were looking for someone who went "above and beyond" for others, which Mrs Underhill clearly did.
She said the expo, which boasted 85 stalls and was celebrating 25 years of service by Age Concern Wairarapa WOOPS, had been a "huge success" thanks to all the community support and sponsors.