In 1993, Sykes became a fashion assistant at British Vogue. An 18th century forebear, the second baronet, Sir Christopher Sykes (1749–1801), was a major figure in the enclosure movement that seized ownership of common land for private use.

Sykes' grandfather, Christopher Sykes (1907–1986), whom she knew as 'Fat Grandpa' or 'F.G.', was a friend and official biographer (1975) of the novelist Evelyn Waugh and son of the diplomat Sir Mark Sykes, sixth baronet (1879–1919), associated with the so-called Sykes–Picot Agreement of 1916, by which Britain and France provided for the partition of the Ottoman Empire after the end of the First World War. The effects of this left her impecunious for a while and she received assistance from Worcester to remain at the college.

Sykes' mother Valerie Goad, a dress designer, separated from Sykes' father Mark while Plum was at Oxford. She has published a short memoir of her unsettling first term at university ( Oxford Girl, 2011). In 1988 she went up to Worcester College, Oxford, where she graduated in modern history. From there she went to a private secondary school, Walthamstow Hall, where she was unhappy, and subsequently to Sevenoaks School, an independent boys' school that had begun admitting girls to the sixth form. Among her friends at Ide Hill Church of England Primary School was Rowan Pelling, who became the editor (or 'editrice') of the Erotic Review. Sykes has described herself as a 'painfully shy' child with mousey brown hair and goofy teeth. She was nicknamed 'Plum' (the Victoria plum being a variety of that fruit) as a child. Victoria Sykes was born in London, one of six children including a twin sister, Lucy, and grew up in Sevenoaks, Kent. Victoria Rowland (née Sykes born 4 December 1969), known both professionally and socially as Plum Sykes, is an English-born fashion journalist, novelist, and socialite.

Oxford Girl by Plum Sykes