The Great Seal of George IV was designed by Thomas Wyon who had been appointed Chief Engraver of His Majesty's Seals following the death of Nathaniel Marchant.

Thomas Wyon was the first of five successive members of his family to be given the responsibility of preparing official seals. He also designed a considerable number of medals, including pieces commemorating the British naval victories at the Battles of Cape St Vincent, the Nile and Trafalgar. Furthermore he was the uncle of William Wyon, Chief Engraver at the Royal Mint for 20 years, whose Young Head portrait of Queen Victoria appeared on United Kingdom coins from 1838 to 1887.

The obverse bears an equestrian portrait of the King with the date MDCCCXX in the exergue marking the beginning of the reign. On the reverse the enthroned portrait of the King is viewed from the side, an unusual style which had only been adopted before on the early Seals of George III. To the right of the throne are three female figures representing England, Scotland and Ireland. Wisdom stands to the left, while Justice and Religion can be seen in the background. A seated lion is placed in the exergue and the whole design is surrounded by a broad wreath of oak and laurel leaves.