David Weigel (born September 26, 1981) is an American journalist and columnist at the news website Semafor. Weigel previously covered politics for The Washington Post, Slate, and Bloomberg Politics and is a contributing editor for Reason magazine.

Weigel was born and raised in Wilmington, Delaware. After moving to England in 1998, he graduated from the American Community School in Cobham, Surrey, in "the high Tory London suburbs" of the London commuter belt, in 2000.

He moved to Evanston, Illinois in 2000 and received a Bachelor of Science degree in 2004 from the Medill School of Journalism at Northwestern University, with a double-major in journalism and political science and a minor in history. While at college, Weigel wrote for The Daily Northwestern and was editor-in-chief of the campus's conservative newspaper Northwestern Chronicle. In the summer of 2001, he also had a "fun" internship at the libertarian Center for Individual Rights.

In the 2000 U.S. presidential election, Weigel voted for Ralph Nader, and served as a Delaware college elector for Nader. In May 2002, then-The Daily Northwestern writer and current Bloomberg News reporter Dan Murtaugh noted how "in two years Dave Weigel has gone from being a Ralph Nader-voting uber-liberal to the scorn of the leftist movement at Northwestern" and how Weigel underwent a "180-degree political turn" "after he was turned away from The Daily" and started working for The Chronicle. In February 2003, while enrolled as a junior and working as editor-in-chief of Northwestern Chronicle, Weigel supported the Iraq War and crashed an anti-war protest at Northwestern University.

In the 2004 election, Weigel voted for John Kerry. Weigel later wrote that "[he regrets] the Nader vote, but not the Kerry vote, as a weak Democratic president with a conservative Congress would have been pretty tolerable in retrospect". He voted for Jack Ryan in the 2004 Republican U.S. Senate primary in Illinois.

In early 2007, Weigel became a registered Republican in the District of Columbia in order to vote for Ron Paul at the Republican primary stage of the 2008 presidential election. In November 2008, Weigel voted for Barack Obama, explaining "I really don't think McCain has the temperament to be President or the interest in standing up to a Democratic Congress....I've got the luxury of a guilt-free, zero-impact vote in the District of Columbia, which I would cast for Bob Barr if he was on the ballot".

In January 2011, Weigel stated that he had voted for Republican Patrick Mara in elections to the Council of the District of Columbia, and that he had voted for Mara "every time he's been on the ballot".

In the Republican Party presidential primaries 2012, Weigel voted for Jon Huntsman, despite his having withdrawn from the race, because "If you looked past his whiff of a tax plan (Huntsman recommended using the flat rates that Simpson and Bowles recommended not using), the guy had a few good ideas." In the 2012 general election, Weigel voted for Gary Johnson.