Clarissa; or, The History of a Young Lady is an epistolary novel by English writer Samuel Richardson, published in 1748. It tells the tragic story of a young woman, Clarissa Harlowe, whose quest for virtue is continually thwarted by her family. The Harlowes are a recently wealthy family whose preoccupation with increasing their standing in society leads to obsessive control of their daughter, Clarissa. It is considered one of the longest novels in the English language (based on estimated word count). It is generally regarded as Richardson's masterpiece.
In 2015 the BBC ranked Clarissa 14th on its list of the 100 greatest British novels. In 2013 The Guardian ranked Clarissa 4th on its list of 100 best novels written in English.