This book is devoted to target detection in a class of radar systems referred to as passive multistatic radar. This system is of great interest in both civilian and military scenarios due to many advantages. First, this system is substantially smaller and less expensive compared to an active radar system. Second, the multistatic configuration improves its detection and classification capabilities. Finally, there are many signals available for passive sensing making them hard to avoid.Multistatic Passive Radar Target Detection: A detection theory framework focuses on examining the multistatic passive radar target detection problem using the detection-theory framework, with the aim of presenting the latest research developments in this field. Early methods were based on intuition and lacked optimality, however, more recent methods with a clear theoretical basis have emerged, based on detection theory. The book offers timely and useful information to advanced students, researchers, and designers of passive radar (PR) systems.The book is organized into four parts, with each part addressing a specific aspect of target detection in various radar systems. The first part, consisting of two chapters, covers the fundamentals of PR and traditional target detection algorithms. Part two comprises seven chapters and deals with the target detection issue in passive bistatic radar (PBR) with a reliable reference channel. Part three includes two chapters and focuses on the detection of targets in multistatic PR systems in the presence of noisy reference channels. Finally, part four, which consists of two chapters, discusses the target detection problem in multistatic and MIMO PRs when no reliable reference channel is available.