In 2005, he replaced Carl Wayne as a vocalist in The Hollies. In 1999, Carl Wayne had stepped in when the band's original singer Allan Clarke retired. In addition to providing main vocals on the Hollies' classic hits in live shows, Howarth is well known for his solo acoustic versions of "Here I Go Again", the Bruce Springsteen song "Sandy", and "I Can't Tell the Bottom From the Top". In 2014 he performed "He Ain't Heavy - He's My Brother" at Goodison Park to mark 25 years since the football disaster in Hillsborough.