He was born in Bradford, England in 1925. After two years service in the RAF he became a secondary school teacher, then a writer, before moving to the USA to become editor of a literary magazine. He was one of the very few British juvenile authors of his generation to achieve success in America.

He started writing while he was a teacher in a Secondary Modern school at Dewsbury in the West Riding of Yorkshire in England, his intended audience being "tough, modern kids similar to the ones I teach".

Here, in one of his Birdy Jones novels, Hildick describes a boy organising a stage-coach ambush:

They watched the resultant mêlée with a mixture of amusement and respect, for no-one could help admire Birdy's powers of imagination and stage management. A thin sharp-nosed boy, with cross-eyes and a black lens to his glasses, he didn't get on very well with boys of his own age and spent most of his time with youngsters, spellbinding them with his bright ideas for giving new life to old games.

Although he had emigrated to the U.S.A. in later life, he died in London England.