Younger brother of Twenty One Pilots singer Tyler Joseph who is also a singer himself. He has over 230,000 followers on his zj10 Instagram account.
He and Tyler used to have competitive basketball competitions growing up. They both played for their high school basketball team at Worthington Christian that would go on to share a Central Catholic League championship.
He grew up in a basketball-friendly family, as his father coached Worthington Christian from 1996 to 2005 and his mother became the coach of Olentangy Orange High School in 2013.
He has another brother named Jay and a sister named Madison. He and his girlfriend Tatum Joseph are expecting a baby girl in April 2018.
His brother Tyler performs alongside Josh Dun in Twenty One Pilots.