Austin Collins (born September 18, 1992), better known as Au5 ( ay-yoo-FYVE), is an American electronic musician from New Jersey. Au5's music encompasses a range of electronic genres such as dubstep, house, trance, drum and bass, drumstep and ambient, and he is known for fusing the characteristics of trance and dubstep in his music. Au5 is best known for his releases on Canadian label Monstercat, some of which have received millions of views on YouTube.

Au5's label releases began in 2012, and after winning a Seven Lions remix contest in January 2013, he joined Monstercat. Au5 had several successful releases on the label, such as "Halcyon", with American producer Fractal, "Snowblind", featuring Tasha Baxter, and "Crossroad", featuring Danyka Nadeau. "Halcyon" and "Snowblind" reached number one on Beatport's dubstep charts. Au5 also performed at South by Southwest festival in Austin, Texas, in 2015.

Au5 departed Monstercat in late 2015. He later toured with Swedish producer Liquid Stranger and Israeli duo Infected Mushroom and performed at Motion Notion festival in British Columbia, Canada, in 2016. He also made two releases on British label NoCopyrightSounds, "Lush", with American duo Last Heroes featuring Holly Drummond, and "Closer", featuring Danyka Nadeau. Au5 returned to Monstercat in 2018 with the single "The Journey", featuring Australian musician Trove. Au5 has released a total of five long plays (LPs), most notably "Divinorum" in 2019.

Au5 has collaborated with various artists including BT, Crystal Skies, Fractal, Mr. Bill, Last Heroes and Seven Lions, among others. Dancing Astronaut described him as a "meticulous producer" with a "unique, complex brand of melodic dubstep and surrounding genres".