Who is the current President of the United States as of October 2021?

The current President of the United States as of October 2021 is Joe Biden. He was inaugurated on January 20, 2021, after winning the 2020 presidential election. Biden, a member of the Democratic Party, served as Vice President under Barack Obama from 2009 to 2017 before winning the presidency himself. His administration has focused on various issues including the COVID-19 pandemic response, infrastructure, and climate change, which have been significant topics of public discussion during his time in office.

The other figures mentioned have held important roles in American politics. Donald Trump was the president before Biden, having served from 2017 to 2021. Barack Obama was president from 2009 to 2017, and Nancy Pelosi is the Speaker of the House of Representatives but not a presidential figure. This context helps clarify why Joe Biden is the correct answer in this instance.