Captain Leo Fransen, 75, was struck by a tree while fighting the Hudson fire, burning near the Narran Lakes nature reserve near Lightning Ridge.
Fellow crew members working Thursday afternoon near Walgett rendered first aid to the man until paramedics arrived.
He was taken to a Lightning Ridge medical facility where he later died.
Captain Fransen was a life member of the Diamond Beach RFS brigade, near Taree, after joining the service in 2010.
The long-serving captain was part of a strike team sent to the area from the Mid North Coast and was on its first day of deployment.
RFS Commissioner Rob Rodgers said Captain Fransen’s death would have a significant impact on his brigade, his district, and the wider RFS community.
“Our thoughts are with his wife Margaret, daughter Julia, son Paul and his extended family, as well as his fellow members,” he said.
Commissioner Rogers said he would be visiting Captain Fransen’s family personally.
The NSW Rural Fire Service paid tribute to Captain Fransen on Facebook.
“His passing will be deeply felt across the RFS, but Leo’s ultimate sacrifice demonstrates the daily risks faced by our firefighters,” the organisation said.
“He will continue to inspire his fellow members and form part of our enduring memory.”abcnews