Gardiner was a member of the Dons' 1946, 1948 and 1950 premiership teams, part of the Bombers' post-war golden era.
Teammate Jack Jones said the Essendon family had lost a great person.
"He was a champion bloke and a champion player," Jones told essendonfc.com.au.
"Playing of a half-back flank or in the midfield he was always the first bloke picked in the team. He was a beautiful drop kick and a wonderful mark."
Gardiner played 168 games between 1943 and 1952 and in his last three seasons won the club's "most unselfish player" award.
In his first year at Essendon in 1943 he won the "best first-year player" but he missed the following season with a spinal injury.
He played in his first Grand Final in 1946 and appeared in an incredible six consecutive Grand Finals from 1946 to 1951.
