Born on 10 August 1957 in London, Dominic O'Brien is a British citizen whose working language is English. The city of his birth provided the geographic origin of a life that would come to be defined by two related pursuits: the practice of mnemonics and the writing of books.

O'Brien works as both a mnemonist and an author, two vocations that sit naturally alongside each other. His citizenship is British, and he writes in English. Beyond these coordinates — London, 1957, mnemonist, author — the facts speak plainly and the record rests on them.