Photodissociation has been extensively explored in the last decades for the analysis of peptides and proteins by mass spectrometry (MS). In the photodissociation process, ions interact with photons generating an increment on internal energy that leads to their fragmentation. The specific characteristics of photodissociation techniques have led to improvements in different applications of MS. Among them, the cleavage of molecular bonds in a selective manner, based on the incorporation of chromophore molecules. Moreover, the ability to generate an almost complete array of fragment ions is the main reason for the increment in the utilization of ultraviolet photodissociation (UVPD). This technique has been applied to the most challenging proteomics studies, such as the characterization of posttranslational modifications and protein sequence variations, de novo sequencing, and the analysis of intact proteins. This article is focused on the most recent and relevant developments of infrared photodissociation and UVPD techniques and their application to the study of peptides and proteins.