《冷血》（英语：In Cold Blood）是美国当代文学经典，亦是极重要的分水岭，入选二十世纪最伟大文学之林。本书由美国作家楚门·卡波提于1966年出版的小说，小说详述了1959年一起凶杀案。位于堪萨斯州霍尔库姆的农人赫伯特·克拉特一家惨遭灭门。卡波提获悉此事后，与好友作家哈波·李决定一同前往当地进行调查。他们访问了当地居民与该案的调查人员，摘记了上千页的纪录。凶手狄克与贝利在犯案后不久被逮捕，卡波提随后以六年光阴着成此书。《冷血》被公认是非虚构小说鼻祖及新新闻主义先驱，同时也成了卡波提的经典代表作之一。

In Cold Blood is a non-fiction novel by American author Truman Capote, first published in 1966; it details the 1959 murders of four members of the Herbert Clutter family in the small farming community of Holcomb, Kansas.

When Capote learned of the quadruple murder, before the killers were captured, he decided to travel to Kansas and write about the crime. He was accompanied by his childhood friend and fellow author Harper Lee, and together they interviewed local residents and investigators assigned to the case and took thousands of pages of notes. The killers, Richard "Dick" Hickock and Perry Smith, were arrested six weeks after the murders and later executed by the state of Kansas, and Capote ultimately spent six years working on the book. When finally published, In Cold Blood was an instant success, and today is the second-biggest-selling true crime book in publishing history, behind Vincent Bugliosi's 1974 book Helter Skelter about the Manson murders.