Thessin, James H., 1948-

James H. Thessin (Born April 19, 1948) is an attorney and was a career American diplomat Ambassador to the Republic of Paraguay from 2011 until 2014.

A native of Milwaukee, Wisconsin, Thessin graduated cum laude from Harvard Law School, graduated with a bachelor's degree summa cum laude from the Catholic University of America, and received an Associate of Arts degree at Father Judge Mission Seminary.

His early career was spent as an antitrust attorney for the Federal Trade Commission (1974-1978), counsel for the Senate Foreign Relations Committee (1978-1981) and senior litigation attorney for the Nuclear Regulatory Commission (1981-1982).

Thessin joined the State Department in 1982 as attorney-adviser for Political-Military Affairs. From 1984 to 1985, he served as Assistant Legal Adviser for Human Rights and Refugee Affairs. In 1986, he began working as assistant legal advisor for managaement. He also joined the Office of Government Ethics, and in 1990 he was named the State Department’s Designated Agency Ethics Official. That same year, he became deputy legal adviser for the State Department, providing legal advice on contracting, legislation, diplomatic immunity, and personnel issues.

From 2011 until 2014, he served for three years as the U.S. Ambassador to the Republic of Paraguay. As Ambassador, Mr. Thessin was a tireless advocate for the rights of those less fortunate, whether because of their gender, economic status, or ethnicity. He was a constant witness to the principles of equality and just treatment that the United States represents. He put the weight of the United States behind efforts to fight corruption, to oppose narcotrafficking, and to stop trafficking in persons and arms smuggling.

After returning from abroad, he focused on improving both the human rights performance of foreign security force units and the implementation of laws that regulate the provision of assistance to foreign security forces that commit human rights. He also worked aggressively to prevent and punish acts of sexual exploitation and abuse by UN peacekeepers. After retiring from the U.S. government in September 2016, he worked for two months in Wisconsin on the Hillary for America Campaign.

Thessin has received numerous Presidential awards, performance bonuses, and other awards including the DC Bar Association’s Beatrice Rosenberg Award for Excellence in Government Service and the Federal Bar Association Tom C Clark Award as the Outstanding Federal Lawyer. He and his wife, Marcia, have a son and a daughter.