South Sydney have hailed John Sattler as an embodiment of the club's proud history and one of their greatest players, after he died aged 80.

One of the game's finest ever forwards, Sattler died on Monday after a battle with dementia.

A four-time premiership-winner at the Rabbitohs, Sattler also captained Australia three times and is famously remembered for one of the toughest grand final acts in history.

After playing on with a jaw broken in three places in the 1970 decider against Manly, Sattler lifted the trophy, gave an acceptance speech before going to hospital for treatment.

"If anyone is to epitomise the true spirit of the South Sydney Rabbitohs it is John Sattler," chairman Nicholas Pappas said.

"He bled red and green. He would do anything for his team mates. He never took a backwards step. He always led from the front.

"He was loved by everyone connected with the Rabbitohs, whether it be one of his former teammates who he led to premiership glory, or the man in the street who loved South Sydney just as much as he did.

"He was tough and brave but fair, uncompromising on the field and empathetic off it, and he truly epitomised everything that we want the Rabbitohs to be."

Sattler's broken jaw remains the image that sums up a generation of rugby league famous for gladiatorial battles and physical toughness.

After being punched by rival forward John Bucknall in the fifth minute, Sattler's response was to ask teammates to hold him up so it wasn't obvious he was hurt.

"He tried to say something to me, but all I saw was a basement of four teeth and you just knew that he had broken his jaw," teammate Bob McCarthy recalled in 2018.

"He was talking too so it must have been killing, and he was getting smacked after as well.

"He was a tough man that Johnny Sattler."

Off the field, though, Sattler was known as Gentleman John.

A product of the Newcastle region, Sattler knocked back several contracts in Sydney before agreeing to join Souths, the club his father supported, in 1963.

He stayed there until his retirement from the NSWRL in 1972, and continued to have a close bond with the Rabbitohs until his death.

Former South Sydney captain Bryan Fletcher labelled Sattler a "legend on and off the field" on Monday.

Plaudits also came from as far a Rabbitohs-supporting Prime Minister Anthony Albanese and ARL Commission chair Peter V'landys.

"He was an inspirational leader who, decades after his retirement, took his rightful place at the front of the marches for South Sydney's reinstatement," Albanese tweeted.

Sattler's son Scott, a premiership-winning rugby league player in his own right, revealed in June 2021 that his father had been diagnosed with dementia in 2020.

But the news still rocked the rugby league world on Monday.

Master coach Wayne Bennett and Sattler toured New Zealand together with the Australian side in 1971 and played together for Queensland in 1973.

"My condolences to his family. South Sydney supporters today will be very sad, he was quite a legend at South Sydney," Bennett said on Triple M.

"A great player for them, a player of that era when the game started to change to give us the game we've got today.

"His toughness is certainly well-known and renowned for it, playing with a broken jaw. The position he played, in that era, you had to be really tough."