The Dunedin artist and art educator has won the supreme award Te Tohu Aroha mo Te Arikinui Dame Te Atairangikaahu at the Te Waka Toi Awards, announced in Wellington on Saturday evening.
Ms Webb, who is of Nga Puhi, English, Welsh and Irish ancestry, gained international renown as a print-maker early in her career.
Brought up in the Bay of Plenty, she is a self-described quiet activist, taking inspiration from land issues in her work.
At 81 years old, she said she felt she was almost "past award age'' - but being in her 80s has not diminished her enthusiasm for work.
About a year ago she went to Doubtful Sound in Fiordland with the Department of Conservation to do some work in the area, where she has been a regular visitor since the mid-1990s.
Her recurring theme was "the special places that should be protected, and are not'', she said.
"I hate the renaming of places of original names to new ones.''
A prolific artist, Ms Webb was unsure how many pieces she had created during the course of her career, saying it was "hundreds and hundreds''. She has taught as a senior lecturer at the Otago Polytechnic School of Art in Dunedin, and was made an Emeritus principal lecturer in 2004.
In 2010, she received an honorary doctorate of laws from the university.
It was hard to pinpoint a highlight of her career, but what she had enjoyed most about the New Zealand art world was its collegiality, she said.
"That's been terrific.''
Other award winners this year include children's illustrator Gavin Bishop, Sir Tipene O'Regan and Sir Pita Sharples.
