The 57-year-old monarch was proclaimed king on August 11, 1952, when he was only 17 but he did not exercise his constitutional powers until May 2, 1953.
King Hussein will attend a parade by the armed forces, police and students on Sunday as celebrations are held across Jordan.
The festivities, set to last several days, will be held under the banner: "With King Hussein on the path to democracy, liberty and development."
The streets of Amman have been decked with portraits of the king and Sunday was declared a public holiday.
The king, who is widely held as moderate and pro-Western, has survived assassination attempts, coups, riots and wars and his country is still grappling with the economic fallout from the 1991 Gulf war.