Miniaturized LC has evolved at an exponential rate over the last 50 years. In the past decade, it has received considerable attention in the field of bioanalytical separation science and technology due to the need to measure different classes of biomolecules present in a variety of matrixes on a global scale to gain a deeper understanding of complex biological processes. This field has become a dominant area underpinning the molecular omics research (e.g., proteomics, metabolomics, lipidomics, and foodomics), allowing key insights into the function and mechanism of small to very large biomolecules on a molecular level. This Feature highlights the recent advances in molecular omics focusing on miniaturized LC technology combined with mass spectrometry-based platforms, with a particular emphasis on the strategies adopted and applications using new and sensitive nanoscale analytical methodologies.