Mark Henry Gitenstein (born March 7, 1947) is an American lawyer and diplomat who had served as the United States ambassador to the European Union.

He formerly served as the United States ambassador to Romania from 2009 to 2012; he was nominated by President Barack Obama on June 11, 2009[3] and confirmed by the Senate on July 8, 2009.

[13] The Romanian English-language news daily Nine O'Clock selected Ambassador Gitenstein as "The Foreign Diplomat of the Year for 2011.

[15][16][17] He actively promoted deeper development of Romania's equity markets, as well as a fair and transparent business environment for all investors.

[28][29] On July 27, 2021, President Joe Biden announced the nomination of Gitenstein to be the United States ambassador to the European Union.

[34] As Ambassador, Gitenstein has highlighted the critical role of free media as a safeguard against democratic regression, advocating for increased action and financial support in this domain.

He established innovative frameworks to unite civil society leaders, financial experts, philanthropists, and successful media organizations, formulating policy recommendations for the European Commission to utilize blended-finance equity investments to strengthen independent and pluralistic media ecosystems in the region.