I already posted one of these but want to show them together.
In 1993, the USA and Monaco simultaneously released a commemorative postage stamp honoring her. However, USA federal law forbids postage stamps depicting foreign heads of state, so the USA stamp listed her as "Grace Kelly", while the Monaco stamp listed her as "Princess Grace".
A U.S. postage stamp [Scott#2749] was issued 24 March 1993 in commemoration of the 10th anniversary of her death. The stamp is a joint issue with Monaco [Scott # 1851]. Both stamps were engraved by Czeslaw Slania.
Princess Grace has been honored by numerous countries on stamps as both an actress and as royalty.