He is the eldest grandchild of Rainier III, Prince of Monaco, and American actress Grace Kelly.

[7] Despite his parents not having married in the Church, as required for legitimacy under church law, he and his younger sister and brother were legitimised by Pope John Paul II in February 1993, eight months after his mother was granted an annulment of her first marriage (to Philippe Junot) by a Pope's decree in June 1992,[8] making him and his siblings dynasts and clearing the way for their possible succession to the throne of Monaco.

[14] Since 2004, Casiraghi has been involved, to varying degrees, with the World Association of Children's Friends (AMADE), a philanthropic organization founded in 1963 by his grandmother Grace; it is currently presided over by his mother Princess Caroline.

[15] In August 2006, Casiraghi visited Manila on behalf of a joint venture of AMADE and the Virlanie Foundation.

[21] In July 2012, Princess Caroline released a statement announcing that her son Andrea Casiraghi and Tatiana Santo Domingo had become engaged after a seven-year relationship.

[22][23] She gave birth to a son, Alexandre Andrea Stefano[24] "Sasha" Casiraghi, on 21 March 2013, at Portland Hospital in London, England.

[26] Casiraghi and Santo Domingo were married in a civil ceremony in the Princely Palace of Monaco on 31 August 2013.

[citation needed] His hobbies and interests include reading, football, horse riding, water sports, skiing and collecting Swatch watches.

[citation needed] In December 2011, Casiraghi had his driving licence suspended after being caught speeding at 200 km/h near Lyon, France.