NSW Police Inspector Amy Scott was widely celebrated for her bravery after running towards and then shooting dead Joel Cauchi to end his attack at Bondi Junction in Sydney's east in April 2024.
The mother-of-two was awarded the NSW Police Commissioner's Valour Award and received praise from Prime Minister Anthony Albanese and Premier Chris Minns.
NSW Police Commissioner Mal Lanyon on Monday confirmed Insp Scott has been battling a rare and aggressive form of breast cancer for a number of months.
She has continued to show her face around her command area in Sydney's eastern suburbs, he said, including in the wake of the deadly Bondi Beach terrorist attack in December.
"We want her to know she is surrounded by the unwavering love and support of the entire NSW Police Force," Mr Lanyon said.
"Despite everything Amy is facing, she continues to show the remarkable person that she is by going out of her way to support her workmates, regularly coming into the station to offer comfort and assistance to those impacted by the recent Bondi terror attack."
NSW Police Legacy, which helps support the families of officers, has set up a fundraiser for Insp Scott. It smashed through its $25,000 goal within two hours and had reached $120,000 by 2.30pm.
The plethora of donations highlight how highly her colleagues and the wider community value her, Police Association of NSW acting president Ian Allwood said.
"Long before the incident at Bondi Junction, Inspector Scott had touched the lives of many police officers and community members," he said.
"Her devotion to policing is only matched by her devotion to her family."
Mr Minns said he was devastated to learn of the diagnosis.
"If anyone deserves a break, it's Amy," the premier told reporters.
"She's a genuine bona fide hero, someone we owe a huge debt of gratitude to.
"Not just because of her heroic actions in Bondi Junction a couple of years ago, but she's also been an inspiration for the exact same officers that attended the terrorism event (at Bondi Beach) on the 14th of December."
Insp Scott had been one of the first to call the local commander and offer help when two gunmen opened fire in the deadly Bondi Beach attack, NSW Police Minister Yasmin Catley said.
Beyond her career, Insp Scott has been lauded as a devoted wife and mother to two young boys.
"Amy is widely known as selfless, compassionate, and one of the kindest people you could ever meet," the fundraiser says.
"She is every bit the remarkable human you would think.
"She is fiercely independent and the first to champion others."
Six people were killed and another dozen injured during the stabbing incident at Bondi Junction.
After Insp Scott shot Cauchi, his family issued a statement saying she "was only doing her job to protect others".
Her actions were praised by many during the inquest into the fatal attack.
The coroner's findings are due to be released on February 5.