The Gentleman's Guide to Vice and Virtue

The Gentleman's Guide to Vice and Virtue is a novel by the American writer Mackenzi Lee, published in 2017 by HarperCollins. It is the first book of the Montague Siblings series.

Henry Montague, called Monty, is the son of an English lord and has been sent on the grand tour of Europe with his sister Felicity and his best friend Percy, who is the person he is actually in love with. The three of them travel through France and Italy in the eighteenth century, and what is meant to be an educational year turns into a pursuit involving a stolen object, a set of people who want it back and a chase across the continent. Lee writes the book in Monty's voice, with his own commentary on what he is doing and why, and she gives the period its real politics: Percy is biracial and faces constraints in England that the tour temporarily removes, and Felicity has plans of her own that the family has not been told about.

The series continued with books about the same characters, and the novel's mixture of historical adventure and comedy was one of a number of books in that period to put a queer romance at the centre of a historical story.