Felix Arvid Ulf Kjellberg (/ˈʃɛlbɜːrɡ/ shel-burg, Swedish: [ˈfeːlɪks ˈɕɛlˈbærj]; born on 24 October 1989), better known by his online alias PewDiePie (/ˈpjuːdipaɪ/ pew-dee-py), is a Swedish web-based comedian and video producer, best known for his Let's Play commentaries and vlogs on YouTube.

Born in Gothenburg, Sweden, PewDiePie originally pursued a degree in industrial economics and technology management at Chalmers University of Technology. In 2010, during his time at the university, he registered a YouTube account under the name PewDiePie. The following year, he dropped out of Chalmers to focus on his YouTube channel, much to the dismay of his parents. Having been refused support from them, PewDiePie began working at a hot dog stand to fund his videos. PewDiePie soon gathered a rapidly increasing online following, and in July 2012, his channel surpassed one million subscribers.

Since 15 August 2013, PewDiePie has been the most subscribed user on YouTube, being surpassed briefly in November and December 2013 by YouTube's Spotlight channel. Holding the position since 22 December 2013, the channel has reached over 52 million subscribers as of January 2017. On 29 December 2014, the channel surpassed EMI's music account on YouTube to become the most viewed channel of all time, and as of January 2017, the channel has received over 14.3 billion video views.

PewDiePie refers to his fanbase as the "Bro Army", and individual fans as "bros". Through his Bro Army fanbase, PewDiePie has raised money for charities. Due to his popularity, PewDiePie's coverage of indie games has created an Oprah effect, boosting sales for titles he plays. In 2016, Time named him one of "The World's 100 Most Influential People." PewDiePie lives in Brighton with his girlfriend, Italian YouTube personality Marzia Bisognin.