Sergey Mikhailovich Brin (born August 21, 1973) is an American businessperson best known for co-founding Google with Larry Page. Brin was the president of Google's parent company, Alphabet Inc., until stepping down from the role on December 3, 2019. He and Page remain at Alphabet as co-founders, controlling shareholders and board members. As of September 2023, Brin is the 8th-richest person in the world, with an estimated net worth of $107 billion according to the Bloomberg Billionaires Index.

Brin emigrated to the United States from the Soviet Union at the age of six. He earned his bachelor's degree at the University of Maryland, College Park, following in his father's and grandfather's footsteps by studying mathematics as well as computer science. After graduation, he enrolled in Stanford University to acquire a PhD in computer science. There he met Page, with whom he built a web search engine. The program became popular at Stanford, and they suspended their PhD studies to start up Google in Susan Wojcicki's garage in Menlo Park.