Born in Manchester then in the historic county of Lancashire, he attended the Royal Grammar School, Worcester, before going up to Exeter College, Oxford to read Modern Languages and graduating with first-class honours in 1981 (BA (Oxon) proceeding MA).
In 1982, Robb entered Goldsmiths' College, London to undertake teacher training (as well as French as a Special Subject tutored by Donald Adamson), before pursuing postgraduate studies at Vanderbilt University in Tennessee where he received a PhD in French literature. He was then awarded a junior research fellowship at Exeter College in the University of Oxford (1987-1990), before leaving academia.
He won the 1997 Whitbread Best Biography Award for Victor Hugo, and was shortlisted for the Samuel Johnson Prize for Rimbaud in 2001. Unlocking Mallarmé had won the Modern Language Association Prize for Independent Scholars in 1996. All three of his biographies (Victor Hugo, Rimbaud and Balzac) became New York Times "Best Books of the Year". The Discovery of France by Robb won the Duff Cooper Prize in 2007 and the RSL Ondaatje Prize in 2008. In The Discovery of Middle Earth: Mapping the Lost World of the Celts (2013), he ventures that the ancient Celts organized their territories, determined the locations of settlements and battles, and set the trajectories of tribal migrations by establishing a network of solstice lines based on an extension of the Greek system of klimata; as evidence he presented artistic geometries, road surveying, centuriations and other archaeologically attested pre-Roman alignments.
Elected a Fellow of the Royal Society of Literature in 1998, Robb was appointed a Chevalier of the Ordre des Arts et des Lettres in 2009. Following the publication of his French translation of Parisians: An Adventure History of Paris, he was awarded the Grande Médaille de la Ville de Paris in 2012.
- Le Corsaire-Satan en Silhouette: le milieu journalistique de la jeunesse de Baudelaire (1985) (French)
- Baudelaire lecteur de Balzac (1988), ISBN 2-7143-0279-3 (French)
- Baudelaire (1989), ISBN 0-241-12458-1, translation of 1987 French text by Prof. Claude Pichois
- La Poésie de Baudelaire et la poésie française, 1838–1852 (1993), ISBN 2-7007-1657-4, criticism (French)
- Balzac: A Biography (1994), ISBN 0-330-33237-6
- Unlocking Mallarmé (1996), ISBN 0-03-000648-1
- Victor Hugo (1997), ISBN 0-330-33707-6
- Rimbaud (2000), ISBN 0-330-48282-3
- Strangers: Homosexual Love in the 19th Century (2003), ISBN 0-330-48223-8
- The Discovery of France. A Historical Geography from the Revolution to the First World War (2007), illustrated, 454 pp. W. W. Norton ISBN 0-393-05973-1
- Parisians: An Adventure History of Paris (2010), W. W. Norton ISBN 978-0-393-06724-8
- The Ancient Paths: Discovering the Lost Map of Celtic Europe, ISBN 0-330-53150-6; US title: The Discovery of Middle Earth: Mapping the Lost World of the Celts, ISBN 0-393-08163-X
- Oxford Companion to English Literature (2009)
- Rectors and Fellows of Exeter College, Oxford, 1901-2005
- Balzac: La Comédie humaine (edn critique en ligne) (French)
- Exeter College, Oxford
- International Who's Who (2004)