Chemometrics, a tool often used to uncover hidden patterns in the data, has been integral in qualitative and quantitative analysis in forensic fields. Although it is still nascent, it has been used successfully in forensic chemistry, toxicology, forensic biology, ballistics, etc. Its growth can be attributed to the complex data, containing thousands of variables, produced by modern analytical instruments such as infrared spectroscopy, Raman spectroscopy, gas chromatography-mass spectroscopy (GC-MS), liquid chromatography-mass spectroscopy (LC-MS), and X-ray-based techniques. First, this enormous amount of data is reduced using data reduction techniques such as principal component analysis (PCA) to generate new orthogonal variables known as principal components. Further analysis is done using this variable to achieve pattern recognition, multivariate (qualitative and quantitative analysis), quality control and validation, and source and origin validation. In the present chapter, an attempt has been made to discuss the application of chemometrics in various fields of forensic science. While chemometrics has emerged as a solid tool to differentiate and classify samples of different sources and origins, its effectiveness depends on the efficacy of the sample preparation technique, the samples analyzed, and the sensitivity of the analytical method used.