Brooke-Little was an Honorary Fellow of the Institute of Heraldic and Genealogical Studies and a Chevalier of the Order of the Fleur de Lys. He was Master of the Scriveners' Company from 1985 until 1986, Chairman of the Harleian Society, and President of the English Language Literary Trust for eleven years from 1985 until 1996. His heraldic involvement carried over as a trustee of the Royal Air Force Heraldry Trust and an adviser on heraldry to the National Trust from 1983 until his death.