Simonyi was appointed ambassador to the U.S. in 2002 under the administration of Prime Minister Péter Medgyessy, and presented his credentials on 25 September 2002.

He appeared several times on The Colbert Report, a satirical political show on American cable television.

In 1961, Simony's father's profession as a textile engineer brought the family to Copenhagen, Denmark, where they would live for five years.

From 1984 to 1989 he worked for the now defunct Hungarian Socialist Workers' Party in the foreign relations department with Gyula Horn and László Kovács, both architects of the changes in Eastern Europe in 1989.

On 14 September 2006 Ambassador Simonyi appeared on the American cable television channel Comedy Central's The Colbert Report to discuss a new bridge under construction in Hungary.

Colbert (a U.S. citizen) had hoped the Hungarian government would name the innovative bridge after him, leading to the ambassador's appearance on the show.

[4] He appeared on the 10 April 2007 episode, in response to comments Colbert claimed to have made on his supposed radio show, Colbert on the Ert, about Hungarians' lack of guitar playing talent, in a parody of Don Imus' recent comments about the Rutgers women's basketball team.

After referring to the alleged scandal throughout the episode, the ambassador appeared suddenly in the tag playing an electric guitar live.

The book, published in 2019, is a testament to the power of American and British Rock and Roll and how it became a tool to break the monopoly and the monotony of Marxist ideology "force fed" to the youths of Central and Eastern Europe by Soviet dominated authorities.

He appeared with GoodTime Charlie lewis on famed guitarist Jerry Miller's (of Moby Grape) 2006 Best Friends CD.

You can sometimes find him late at night jamming with musicians at Madam's Organ Blues Bar in Adams Morgan in Washington D.C.

At his visit with Ohio University Global Leadership Center undergraduates, Simonyi described a situation where the world has, as a positive thing, become affixed to ideas based in American innovation.