One of the heroes of the Maroons' domination of Origin in the late 1980s, Backo died surrounded by family in his home town of Cairns on Sunday.
The former Canberra and Brisbane forward had been battling a melioidosis infection in recent months, and suffered a heart attack two years ago.
Backo played seven Origins for the Maroons between 1988 and 1990, but his impact was immense.
The front-rower became the first front-rower to be named man of the match in two straight Origins, as Queensland romped to a 3-0 sweep in Backo's rookie series.
"Sam was a wonderful player for Australia and Queensland, where he was always entertaining in our team bus with his dry humour," Broncos and Maroons teammate Gene Miles said.
"He was an old-fashioned front-rower but very quick for his size too. He always made plenty of yards every time he took the ball up.
"He made his debut for Queensland in 1988 and made an immediate mark with two man of the match awards in a row in that series.
"You just knew he would outplay the opposition and from those fantastic Origin displays he got picked to play for Australia."
Backo played six Tests for Australia in 1988 and 1989, and was in 2008 named in the Indigenous team of the century.
"There was not a guy in Queensland camp that didn't like Sam. He was such a loveable big unit," Miles said.
"We had a lot of fun with him. He had a special spot at the back of the team bus with all the big forwards.
"I'd sit up front with Wally (Lewis) and with all the windows shut we would whack the back heaters on high heat and Sam and Martin Bella would blow up.
"All we could hear from the back was, 'Turn that off'."
Away from rugby league, Backo continued to work in the Indigenous space after his 1990 retirement, engaged in a community development program assisting people on their release from jail.
Born in Ingham, Backo's mother Dr Evelyn Scott was an Aboriginal rights activist who played a key role in the 1967 referendum which gained citizenship for Aboriginal and Torres Strait Islander people.
"I am proud to be a north Queensland rainforest Murri," Backo told the Former Origin Greats magazine in 2022.
"I was playing for my mob and for all the blackfellas. We came through the struggle and we stood up and were counted."
ARL Commission chairman Peter V'landys also paid tribute to Backo - the man and the footballer.
"Sam was as tough as they come, a larger-than-life character who was as recognisable as he was resilient," V'landys said in a statement.
"Through a successful career with Canberra Raiders, Brisbane Broncos, not to mention Queensland and Australia, he was a one-of-a-kind footballer.
"A member of the Indigenous Team of the Century, Sam was also a generous and selfless man who was passionate about Indigenous health and advocacy away from the field."
6°C