Zachary Weinersmith (born Zachary Alexander Weiner) is an American cartoonist, who is best known for his webcomic Saturday Morning Breakfast Cereal (SMBC). He is the author of two other webcomics, the completed Captain Stupendous with artist Chris Jones, and Snowflakes, co-written by James Ashby and also illustrated by Chris Jones. He also founded the sketch comedy group SMBC Theater with James Ashby and Marty Weiner in 2009.

Weinersmith has been involved in writing and drawing comics since his high school years, but he first published on the internet in the late 1990s. His early comics usually had three or more panels, but after 2002, he switched to drawing predominantly one panel comics. He stated in a 2009 interview that he was glad to have decided to draw one panel comics because he felt three panel webcomics had become a webcomic cliche by that time, and that there were almost no decent one panel comics on the internet. More recently, he has drawn a mixture of single and multi panel comics for SMBC.

Weinersmith's webcomic was recognized in 2006, and 2007 with the Web Cartoonists' Choice Award for Outstanding Single Panel Comic,[3] and received nominations in 2003,[4] and 2008.[5]

SMBC is at heart a geek comic, which nevertheless addresses a broad range of topics, such as love, relationships, economics, politics, religion, science, and philosophy. As shown by the diverse range of blogs listed above, it appeals to many different groups.

SMBC has around 250,000 daily readers, served over 300,000,000 comics in 2010, and is one of the fastest growing comics online (has sextupled in readership since 2008). The comics have been featured on many important blogs, including The Economist, Glamour, BoingBoing, Bad Astronomy, Blastr, Blues News, Joystiq, Washington Post, Freakonomics, and more.

Zach has a degree in Literature and 3/8ths of a degree in physics. He enjoys reading about math, logic, science, history, fiction, and philosophy. His hobbies are space travel, dinosaur riding, and wishful thinking. He currently lives in southern California with his beautiful and brilliant wife.

Note: Zach publishes SMBC and SMBC material under both "Zach Weiner" and "Zach Weinersmith".