He passed away peacefully on Monday in Rome “And did not suffer from pain”, his son said.
Spencer, whose real name was Carlo Pedersoli, was known among his fans as the “Big friendly giant” of the screen because of his height and weight.
Spencer, who was also a professional swimmer, played in more than 20 films from the 1950s to the 1980s.
Spencer was born in the southern Italian city of Naples in 1929, but later moved to Rome, w he became a promising swimmer.
In 1950, he was the first Italian to swim 100m in under one minute.
He later abandoned his sporting career and began playing in westerns and comedy films, often alongside Terence Hill.
Spencer appeared in movies including Ace High, They Call Me Trinity and A Friend is a Treasure.
Spencer said he chose his name as a tribute to his favourite beer Budweiser and US actor Spencer Tracy.