Redmond grew up in Huyton, Lancashire. He passed the 11 plus examination but was given a place at St Kevin's Comprehensive School, a large Catholic boys school in Kirkby. Upon leaving school at 18 with 4 GCE O Level passes and one A level, he trained as a quantity surveyor. Then in his twenties he decided to try for a career as a writer and he gained a Social Studies Degree from Liverpool University, before writing scripts for TV sitcoms such as The Squirrels. He then came up with the Grange Hill concept in 1978, for which he drew upon his own experience of the Comprehensive system.

He was the Creative Director of Liverpool's 2008 European Capital of Culture.

In 1993, he caused a large amount of controversy after ITV's Emmerdale brought him in to think of a way to attract larger viewing figures to the soap opera. His solution was a plane crash over the village, killing and wounding many residents. The timing of the storyline — close to the fifth anniversary of the Lockerbie disaster — caused complaints.

In 1989, Phil Redmond was awarded the post of Honorary Professor of Media Studies at Liverpool John Moores University, where he is encouraging a new, practically-orientated, media studies course.

He was awarded the CBE (Commander of the Order of the British Empire) in the 2004 Queen's Birthday Honours List for services to drama.