Clawson enjoyed a distinguished career as a forward with Featherstone, Bradford, Leeds, Oldham, York, Wakefield and Hull from 1962-1980 and was capped 14 times by Great Britain.
He famously fought off a severe bout of tuberculosis to enjoy a 23-year career which brought him more than 2,500 points from 640 appearances.
He won a Championship final with Leeds in 1972, when he won the Harry Sunderland Trophy as man of the match, but his finest hour came later that year when he was a member of the Great Britain team that won the Rugby League World Cup in France.
"Our thoughts are with Terry's family at this very sad time," RFL chief executive Nigel Wood said.
"It is particularly sad and poignant that Terry's passing has come in this, a World Cup year.
"Terry will not just be remembered as a great rugby league player - he will be remembered as one of the game's great characters."
A funeral service will take place at Pontefract Crematorium next Thursday.
Leeds' players will wear black armbands in Thursday night's Super League game at Wigan as a mark of respect for both him and former general manager Joe Warham, who also passed away this week.