Abstract
<jats:title>Abstract</jats:title> <jats:p>Over the past decades, the chemical characterization of single cells has improved immensely to allow the single‐cell omics analysis of metabolites, lipids, and peptides at the large scale. This progress has been enabled by new and improved strategies for ionization and sampling, where a multitude of techniques for single‐cell mass spectrometry (MS) have contributed unique insights to many different disciplines. In particular, the improvement in the automation and parallel processing of single‐cell samples has greatly contributed to single‐cell proteomics, which can routinely identify thousands of protein groups from a single mammalian cell. Here, we review the single‐cell mass spectrometry ionization techniques and their applications, as well as recent advances in single‐cell proteomics, metabolomics, and lipidomics technologies.</jats:p>