Daniel Baer, the out U.S. ambassador to the Organization for Security & Cooperation in Europe, married his partner Brian Walsh last weekend in Vienna, Austria.
Baer is the seventh openly LGBT person appointed by President Barack Obama and the first to a multilateral institution.
The ambassador tweeted a photo of the ceremony and thanked Obama, former Secretary of State Hillary Clinton, and Secretary of State John Kerry for their commitment to equality.
Baer and Walsh live in Vienna, the headquarters of the OSCE, since 2013 September.
Baer tweeted: "So, I got married this morning.
Thank you @BarackObama, @HillaryClinton, & @JohnKerry
for your commitment to equality."