Caddel was born in Bedford and grew up in Gillingham, Kent. He studied music at Newcastle University, but changed to English after meeting Bunting and Tom and Connie Pickard. He helped the Pickards organise the seminal Morden Tower poetry readings.
Caddel's work was influenced by Bunting, Ezra Pound and Lorine Niedecker and also by the English landscape tradition as represented by John Clare, with whom he shared a birthday.
He published a number of small pamphlets, most of which were collected in three books; Sweet Cicely (1983), Uncertain Time (1990) and Larksong Signal (1997) A selected poems, Magpie Words appeared in 2002. His final book, Writing In The Dark, was published in late 2003.
With his wife Ann, Caddel ran Pig Press, through which he published a number of the more interesting avant-garde British, Irish and American poets of the latter half of the 20th century.
Caddel edited Buntings Uncollected Poems in 1991 and his Complete Poems in 1994. With Peter Quartermain, he edited the anthology Other: British And Irish Poetry Since 1970 (1998). A lifelong asthmatic, Caddel died of leukaemia on April Fool's Day, 2003.