Gunnar Sizemore is an American actor who portrayed Micah Brenner on Nashville.
He is known for his work on Nashville, The Book of Life and Clarence. He was nominated for Best Actor in the 2013 film Heartfall at the 168 International Film Festival 2013. Sizemore is the voice of Billy Billions on the Cartoon Network show Ben 10, and of Ezri on Shimmer and Shine for Nickelodeon. Sizemore lent his voice to the character of Ralf in the stop-motion film I'm Scared. He started a YouTube channel called MondayShorts where he shoots short films and posts them on Mondays.