Long-serving Wollongong Labor councillor Vicky King died suddenly on Tuesday night, collapsing after a public meeting at Berkeley.
Wollongong Lord Mayor Gordon Bradbery said the council was saddened to hear of Cr King's death and that she had "served her community right to the end".
Just before she collapsed, apparently suffering a heart attack, she had been attending a Neighbourhood Forum 7 (Berkeley) community meeting at the Yacht Club.
"She seemed very well, she was sitting right next to me and contributing to the debate," Cr Bradbery said, noting the meeting had finished and most people had left before Cr King collapsed.
"Paramedics came worked on her, but unfortunately she passed away."
"Our thoughts and prayers are with her husband Charlie, their children and grandchildren at this difficult time.
Cr King, who was in her late 60s, served as a Labor councillor for 19 years. She was reelected in 2017 after a 13 year hiatus, originally joining the council in 1987 until 2004, the council said.
Cr Bradbery said Cr King was "a passionate advocate for all in our community, and in particular the residents of Ward 3 in our southern suburbs, and was a strong promoter of Wollongong."
Deputy Lord Mayor Tania Brown said Cr King's Labor colleagues were shocked to hear of her death.
"At the council meeting on Monday night she was absolutely full of life, telling stories of her recent trip to London," she said.
"She was also a huge supporter of me becoming deputy mayor, telling me the types of things I needed to do and committees I should join, and she was a passionate advocate for getting more women in local government," Cr Brown said.
Together, the five remaining Labor councillors paid tribute and said she was a tireless campaigner.
"Vicky was passionate about many things but foremost her family, her community and the ALP, and fought tirelessly for all three," she said.
"She was a proud Labor women, a life member, who worked to make her community more inclusive, greener and sustainable, one that recognised diversity and supported those who needed a helping hand.
The region's Labor MPs also expressed their sadness.
"Vicky has always been a trailblazer, when she was first elected to ... in 1987, she would often bring her young daughters Hannah and Matika to council meetings; at first this would raise a few eyebrows but soon this became the accepted norm," she said.
"Apart from serving on Wollongong City Council, Vicky was an accountant who helped thousands and thousands of people in the region manage their financial affairs."
On social media, Greens councillor Mithra Cox said she was "shocked and saddened to wake up this morning to hear that Labor Councillor Vicky King died last night".
"Vicky always spoke up to protect the environment and for the less well off in our city," she said.