Antimicrobial resistance is a major public health threat, due to the emergence of new bacterial strains not responding to classical antibiotics. This review focuses on the use of transition metal cross-coupling strategies used to access new β-lactam derivatives, the most well-known and commonly used antibiotics. This manuscript covers the seminal studies for the synthesis of antibiotics up to the current need of accessing specific probes (by functionalizing existing drugs), crucial for the detection of resistances. These strategies also allow the linkage of a cargo to a β-lactam antibiotic for selective release for either therapeutic effect or for diagnostic purposes (in the case of probes), which will be explained in this article.