Who is president?

As of my knowledge update date in September 2021, the president of the United States is Joseph Biden. He was elected in the November 2020 presidential election, defeating then-incumbent Donald Trump. Please note that this information may be outdated due to the passing of time and the occurrence of elections since then. To get the most up-to-date information on the current president, I recommend visiting reliable sources such as official news outlets or the White House website.