Johnston, a left-arm medium-pace bowler from Victoria, played 40 Tests for Australia between 1947 and 1955, taking 160 wickets at 23.91.
Cricket Australia said he died in a Sydney nursing home late Thursday.
His death leaves five surviving members of the 1948 team that toured England unbeaten -- Arthur Morris, Neil Harvey, Sam Loxton, Bill Brown and Ron Hammence.
Cricket Australia chairman Creagh O'Connor said Johnston was an "invincible on the field during his distinguished 40-Test career, and a gentleman off the field.
"Those of us fortunate enough to have known Bill will remember him as a good companion, well-humoured, passionate about cricket and always willing to share his knowledge," O'Connor said in a statement.
"However, to cricket fans he will always be remembered, rightly, as a member of Sir Donald Bradman's legendary Invincibles, and as a left-armer who took a lot of wickets quickly and economically when bowling in the company of fellow greats such as Lindwall and Miller.
"His cheery tail-end batting also had its moments, including a quirky statistic that gave him a batting average of 102 during a tour of England in 1953."
Johnston captured 554 first-class wickets at 23.35, and was a Wisden Cricketer of the Year in 1949.