Matthew H. Tueller (born 1957) is an American diplomat who currently serves as the United States Ambassador to Iraq. He is a career foreign service officer. Prior to his current ambassadorship, he served as the United States Ambassador to Kuwait (2011-2014) and Yemen (2014-2019).

A Utah native, Tueller grew up in in Europe, North Africa, and Latin America, including four years in Tangier, Morocco. He earned a B.A. in International Relations from Brigham Young University (BYU) in 1975 and a Master’s in Public Policy from the John F. Kennedy School of Government at Harvard University in 1984. After graduating from Harvard, he worked for a year as an official in the Reagan administration.

Tueller joined the Foreign Service in 1985 and served as Egypt desk officer from 1989 to 1991. Early overseas assignments included political officer at the embassy in Kuwait, political officer and consular officer at the embassy in Amman, Jordan, political officer at the embassy in London and deputy chief of mission at the embassy in Doha, Qatar.

In the aftermath of the October 2000 terrorist bombing of the USS Cole in Aden, Yemen, Tueller was made chief of the U.S. Office in Aden, overseeing the inter-agency investigation into the bombing, a task that kept him there until February 2001. He then served as political counselor at the embassy in Riyadh, Saudi Arabia. He returned to Kuwait as deputy chief of mission from 2004 to 2007, and served as political minister counselor at the embassy in Baghdad, Iraq, from July 2007 to July 2008. Thereafter, Tueller served as deputy chief of mission at the embassy in Cairo, Egypt from August 2008 to May 2011.

In 2011, Tueller reached his long-time goal of becoming an ambassador when he was sworn in as the U.S. envoy to Kuwait, arriving in Kuwait on September 23, 2011. He remained in this position until April 28, 2014.

With growing turmoil in Yemen calling for an ambassador who could keep his cool under difficult conditions, Tueller was sent to Sanaa, Yemen, where he would serve from May 8, 2014 to May 16, 2019. In this role, he was involved in negotiations between Yemen's Houthi forces and partners of the Saudi-led coalition during the course of the Yemeni civil war.

On November 7, 2018, the White House announced the president’s intent to nominate Ambassador Tueller to be the next United States Ambassador to Iraq. On May 16, 2019, the United States Senate confirmed the nomination of Matthew Tueller to be United States Ambassador to the Republic of Iraq. He undertook his third ambassadorship effective June 9, 2019.

Tueller is married to DeNeece Gurney and has five children. In addition to English, Tueller is fluent in Arabic.