Derek Alexander Muller (born 9 November 1982)[3] is a science communicator and media personality, best known for his YouTube channel Veritasium, which has over 17 million subscribers and 3 billion views as of February 2025.

[3] Since 2011, Muller has continued to appear on Catalyst, reporting scientific stories from around the globe,[9] and on Australian television network Ten as the 'Why Guy' on the Breakfast program.

[11] He presented the documentary Uranium – Twisting the Dragon's Tail, which aired in July–August 2015 on several public television stations around the world and won the Eureka Prize for Science Journalism.

[16] Muller presented in film Vitamania: The Sense and Nonsense of Vitamins, a documentary by Genepool Productions, released in August 2018.

[25] The number was chosen because it is "The Answer to the Ultimate Question of Life, The Universe, and Everything" in Douglas Adams' famous novel The Hitchhiker's Guide to the Galaxy.

[28] In 2021, Muller hosted Pindrop, a YouTube Original series exploring unusual places around the world, as seen from Google Earth.

[37] After a video was posted in which Muller is shown driving a wind-powered car, equipped with a huge spinning propeller, faster than the wind, UCLA physics professor Alexander Kusenko disagreed with the claim that sailing downwind faster than wind was possible within the laws of physics, and made a $10,000 bet with Muller that he could not demonstrate that the apparent greater speed was not due to other, incidental factors.

[38] After Derek Muller's parents, Anthony and Shirley, married in South Africa, they moved to Vancouver, British Columbia, Canada, where his two sisters were born (Kirstie and Marilouise).

[3] After Muller moved to Los Angeles, United States, he met Raquel Nuno, a planetary science Ph.D. student[39] whom he married.