Barack Obama served as president of the United States from January 20, 2009, to January 20, 2017.

He was first elected in November 2008 and took office on January 20, 2009, as the 44th president. He then won re‑election in November 2012 and served a second four‑year term that ended when his successor, Donald Trump, was inaugurated on January 20, 2017.