Quantum entanglement and Bell inequality violation at colliders have become a significant area of research in particle physics. This review discusses the study of entanglement and Bell inequality violation in various final states, including top-quark pairs, tau-lepton pairs, Lambda baryons, and vector mesons. The paper outlines the theoretical foundations of entanglement and Bell locality, the tools used to analyze these phenomena, and the experimental results obtained from collider experiments. It also explores the potential of entanglement as a tool for probing new physics beyond the Standard Model. The paper begins by introducing the concept of quantum entanglement and its implications for quantum mechanics. It then discusses the connection between entanglement and Bell locality, explaining how quantum correlations can violate Bell inequalities, which are expected in classical physics. The paper presents the necessary tools for analyzing entanglement, including polarization density matrices and quantum state tomography. The review then focuses on specific systems, such as qubits and qutrits, and their relevance to collider physics. It discusses the analysis of entanglement in various particle systems, including top-quark pairs, tau-lepton pairs, and Higgs boson decays. The paper also addresses the implications of entanglement for probing new particles and fields beyond the Standard Model. The study of entanglement in particle physics has gained momentum in recent years, with experiments at colliders providing insights into quantum correlations and Bell inequality violations. The paper highlights the importance of entanglement in understanding the fundamental nature of quantum mechanics and its potential applications in high-energy physics. It also discusses the challenges and limitations in testing Bell inequalities at colliders, as well as the potential for using entanglement to explore new physics. The review concludes with an outlook on future research directions and the potential impact of entanglement studies on particle physics.Quantum entanglement and Bell inequality violation at colliders have become a significant area of research in particle physics. This review discusses the study of entanglement and Bell inequality violation in various final states, including top-quark pairs, tau-lepton pairs, Lambda baryons, and vector mesons. The paper outlines the theoretical foundations of entanglement and Bell locality, the tools used to analyze these phenomena, and the experimental results obtained from collider experiments. It also explores the potential of entanglement as a tool for probing new physics beyond the Standard Model. The paper begins by introducing the concept of quantum entanglement and its implications for quantum mechanics. It then discusses the connection between entanglement and Bell locality, explaining how quantum correlations can violate Bell inequalities, which are expected in classical physics. The paper presents the necessary tools for analyzing entanglement, including polarization density matrices and quantum state tomography. The review then focuses on specific systems, such as qubits and qutrits, and their relevance to collider physics. It discusses the analysis of entanglement in various particle systems, including top-quark pairs, tau-lepton pairs, and Higgs boson decays. The paper also addresses the implications of entanglement for probing new particles and fields beyond the Standard Model. The study of entanglement in particle physics has gained momentum in recent years, with experiments at colliders providing insights into quantum correlations and Bell inequality violations. The paper highlights the importance of entanglement in understanding the fundamental nature of quantum mechanics and its potential applications in high-energy physics. It also discusses the challenges and limitations in testing Bell inequalities at colliders, as well as the potential for using entanglement to explore new physics. The review concludes with an outlook on future research directions and the potential impact of entanglement studies on particle physics.