Michael George Glen Waltz (born January 31, 1974) is an American politician, diplomat, businessman, author, and former Army Special Forces officer who has served as the 32nd United States ambassador to the United Nations since September 2025 in the second Trump Administration. A member of the Republican Party, he previously served as the 29th national security advisor from January to May 2025 and was the U.S. representative for Florida's 6th congressional district from 2019 to 2025. He was the first Army Special Forces soldier to be elected to Congress. Waltz received four Bronze Stars while serving in the Special Forces during multiple combat tours in Afghanistan, the Middle East, and Africa. He served in the Bush administration as a defense policy director in the Pentagon and as counterterrorism advisor to Vice President Dick Cheney.

In 2018, Waltz was elected to the House of Representatives, defeating former ambassador Nancy Soderberg and succeeding Ron DeSantis, who was elected governor of Florida that same year. Waltz was re-elected in 2020, 2022, and 2024 with over 60% of the vote in each election. He was chair of the House Armed Services Subcommittee on Readiness for the 118th United States Congress. Waltz was considered one of Congress's most hawkish members with regard to China, believing the Chinese Communist Party (CCP) is in a cold war with the U.S. and the West.

In 2021, Waltz was the first member of Congress to call for a full U.S. boycott of the 2022 Winter Olympics in Beijing over what he described as the CCP's genocide and internment of Chinese Uyghur populations and the enslavement, forced labor, and internment camps of ethnic minorities in China. On November 12, 2024, President-elect Trump announced he would appoint Waltz to serve as national security advisor in his second administration. Waltz resigned his House seat prior to taking office on January 20, 2025.

On May 1, 2025, it was reported that Waltz, along with Deputy National Security Advisor Alex Wong, would leave their posts following group chat leaks on the messaging platform Signal. Waltz served as NSA for 101 days, the second shortest tenure for a non-acting officeholder in the position (Mike Flynn, Trump's initial first term NSA, lasted 24 days). The same day, Trump announced via social media that he intended to nominate Waltz to serve as Ambassador to the United Nations (replacing the withdrawn nomination of Elise Stefanik) and that Marco Rubio would take on an acting role as National Security Advisor.

Waltz was born on January 31, 1974 to a single mother in Boynton Beach, Florida, and grew up in Jacksonville, where he graduated from Stanton College Preparatory School. He earned a Bachelor of Arts degree in international studies from the Virginia Military Institute in 1996, graduating with honors as a Distinguished Military Graduate.

Waltz was commissioned as an armor officer in the U.S. Army in 1996. He later graduated from Ranger School and graduated from the Special Forces Qualification Course in 2000, then serving two years as an active duty Special Forces officer with multiple tours in the Middle East and Africa. For his actions in combat, Waltz was decorated with four Bronze Stars, including two for valor.

From 2002 to 2011 and 2016 to 2023, Waltz served in Company B, 2nd Battalion, 20th Special Forces, MD-ARNG. From 2012 to 2015, he served in 5th Battalion, 19th Special Forces, TX-ARNG.

Waltz worked in the Pentagon as a defense policy director for secretaries of defense Donald Rumsfeld and Robert Gates. He went on to serve in the White House as the vice president's counterterrorism advisor. Waltz wrote Warrior Diplomat: A Green Beret's Battles from Washington to Afghanistan.