The English-born 26-year-old has previously expressed interest in representing the U.S. national team upon obtaining his citizenship.
"This country has given me a lot over the past five years, and I look forward to giving back as much as possible," Dwyer said in a news release. "I want to thank everyone who has supported me on this journey, most importantly my family and my club. This was a very meaningful day for me, and I’m excited to start the next chapter of my life as a U.S. citizen."
Dwyer has lived in the U.S. since 2009 and received his green card in February 2012, a month after Sporting KC selected him out of South Florida in the first round of the MLS draft. He has been married to U.S. national team forward Sydney Leroux since 2015.
Dwyer is now poised to join a U.S. forward pool that includes Bobby Wood, Jozy Altidore, Clint Dempsey, Jordan Morris, Gyasi Zardes, Chris Wondolowski and Juan Agudelo.
"That's a strong side you've got there, there's some fantastic players in that squad," Dwyer said of the U.S. in January. "I'm just working hard and playing well, and if I'm selected and if I'm on it, I hope I can get an opportunity and take it."