Roger Dean Carstens is an American diplomat and retired United States Army Special Forces lieutenant colonel.

[2] During his work as the Special Presidential Envoy for Hostage Affairs, Carstens has negotiated the release of over a dozen Americans wrongfully detained or held hostage abroad including Brittney Griner, Philip Walton, Trevor Reed, Danny Fenster, Baquer Namazi, the Citgo Six, Osman Khan, Matthew John Heath, Mark Frerichs, and Jorge Alberto Fernández.

[3] Carstens went on to earn a Bachelor of Science degree in diplomatic and strategic history from the United States Military Academy in 1986.

[4][5] Carstens was class president at West Point and [6] became interested in joining the military after reading about injustices around the world including the Cambodian genocide.

[13] Daniel Pinéu, a professor at Amsterdam University College, wrote that Carstens is the embodiment of the phrase "an officer and a gentleman.

[19] Carstens previously served as the deputy assistant secretary in the Bureau of Democracy, Human Rights, and Labor.

[20] He also advocated, among other things, to protect the human rights of women in Syria in the midst of the Syrian civil war.

[19] Jason Rezaian, a journalist and former wrongful detainee in Iran, wrote an op-ed asking President Biden to keep Carstens in his position.

It's much better … [we] feel like he's really there for the families.”[24] Carstens supported President Biden's executive order that seeks to help American's unlawfully detained abroad and prevent such wrongful detentions.

[29] In April 2022, Carstens negotiated the release of Trevor Reed as part of a prisoner exchange for Konstantin Yaroshenko, a Russian pilot convicted of drug smuggling.

[33] Carstens travelled to Syria during the first presidency of Donald Trump to try to negotiate for the release of Austin Tice and Majd Kamalmaz.

[35] In October 2022, Carstens negotiated a prisoner exchange that resulted in the release of seven Americans, including the remaining five of the Citgo Six, Matthew John Heath, and Osman Khan.