Javier "Harvey" Guillén (born May 3, 1990) is an American actor. He voices Nightwing on Harley Quinn. He also voiced Alvin (Batman's pedal butler) in "Gotham's Hottest Hotties".
He is best known for his role as the human familiar Guillermo de la Cruz in the 2019 television series What We Do in the Shadows and has appeared in recurring roles on shows such as Huge (2010), The Thundermans (2013–2018), Eye Candy (2015), and The Magicians (2017–2018). He also appeared in the 2013 film The Internship. He also voiced Perrito in the 2022 film Puss in Boots: The Last Wish and played Dr. Jose Francisco Morales Rivera de la Cruz / "Sanchez" in Blue Beetle.