Cottrell-Boyce was born in 1959 in Rainhill, to a Catholic family. He attended St Bartholomew’s Primary School in Rainhill and West Park Grammar School.

In addition to original scripts, Cottrell-Boyce has also adapted novels for the screen and written children’s fiction. His first novel Millions was based on his own screenplay for the film of the same name; it was published by Macmillan in 2004. Cottrell-Boyce won the annual Carnegie Medal from the British librarians, recognising it as the year’s best children’s book published in the U.K. His next novel Framed, he made the shortlist for both the Carnegie and the Whitbread Children’s Book Award. He adapted it as a screenplay for a 2009 BBC television film. He made the Carnegie shortlist again for Cosmic (2008). In 2011, he was commissioned to write a sequel to the Ian Fleming children’s book Chitty Chitty Bang Bang, which was published in October 2011 as Chitty Chitty Bang Bang Flies Again In addition to Coronation Street, he wrote many episodes of the soap opera Brookside, as well as its spin-off Damon and Debbie.

He wrote and staged his first original theatre production Proper Clever at the Liverpool Playhouse during the city’s European Capital of Culture Year, in 2008. On 18 September 2010, he co-presented the Papal Visit at Hyde Park with TV personality Carol Vorderman. In June 2012, he assumed the position of Professor of Reading (the first such professorship) at Liverpool Hope University.

Cottrell-Boyce was made an Honorary Doctor of Literature at Edge Hill University on 16 July 2013. In 2014, Cottrell-Boyce wrote an episode of Doctor Who, titled “In the Forest of the Night”. He also wrote the second episode of the tenth series, “Smile”. In September 2015, Cottrell-Boyce held the keynote speech at the Children´s and Young Adult Program of the 15th international literature festival berlin.

In January 2018, he was on the victorious Keble College, Oxford University Challenge “famous alumni” team; he got almost all of the points scored by Keble (total score 240) and was lionized on social media as a consequence; Reading University scored 0 in that game, thus making television history.