Morley was born in Chorley Hospital in Chorley, Lancashire, England. He was the only child born to engineer father Frank Morley and his mother Phyllis Morley. He was educated at St. Peters Church of England School and Elementary School until the age of twelve and then he attended Ashworth College until he was fifteen. Morley left school with no qualifications. His best friend at school was Peter Smith. Ken trained as an apprentice mechanic and in September 1963 he enrolled at Alston Hall College where he gained six O Levels and two A Levels. In 1966, he moved to London to become a primary school teacher in Holloway Road. He then moved back to Lancashire and became a supply teacher, mainly in History and English. Later in his teaching career, Ken was a teacher at Smithills High School in Bolton, Craigmount School in Edinburgh and Archbishop Tennison School in London. His father Frank died on 1 April 1970.
Morley has been a regular on British television since the 1970s, his earliest role being in an episode of The Fall and Rise of Reginald Perrin. His first major role television role was playing General Leopold von Flockenstuffen in the BBC war sitcom 'Allo 'Allo! starring in the show from 1988 to 1991. From 1989 to 1995, he played eccentric shop assistant Reg Holdsworth in the ITV soap opera Coronation Street. He became a household name for the role of Reg Holdsworth and the character's spectacle glasses. He left the show in 1995, to pursue other acting roles and projects. In 1997, he appeared as a Librarian in the children's television show Woof! and guest starred as Nazi Captain Voorhese in the sitcom Red Dwarf. In 1998, he appeared in an episode of the television show The Grand as Harry Frindel. In 1999, Morley returned to Coronation Street in the spin-off show Coronation Street: After Hours alongside former Coronation Streetactress Julie Goodyear. He has also appeared in Emmerdale spin-off show Emmerdale: Don't Look Now! - The Dingles in Venice playing Reg Holdsworth.
In 2003 to 2004, Morley starred in the sitcom Hardware as Rex alongside Martin Freeman.
In 2005, he was a contestant in the ITV television show Celebrity Fit Club, where he lost over two stone.
Ken also appears in the adverts for Safestyle UK double glazing windows. He features as a character similar to Reg Holdsworth.
Morley is a pantomime favourite and has appeared in a many pantomimes including: Jack and the Beanstalk, Aladdin, Snow White, Sleeping Beauty and lots more.
In 2010, Ken returned to Coronation Street in the 50th Anniversary Special Coronation Street: A Knights Tale alongside former Coronation Street actor Kevin Kennedy who played Curly Watts.
In 2011, he appeared in an episode of the children's television show Sooty as Hurbert Fanshawe.
Morley has promoted and appeared in the adverts Coronation Street Bingo for Gala Bingo.
In 2014, he guest starred in the ITV sitcom Benidorm as Herbert.
In mid 2014, he was a contestant in the BBC cookery show Celebrity Masterchef.
In January 2015, Morley participated in the fifteenth series of the Channel 5 show Celebrity Big Brother. He entered the house on Day 1 as a Housemate and Contestant. On 12 January 2015, he was removed from the Big Brother house for using "unacceptable and offensive language". Ofcom had earlier received 233 complaints about his behaviour.