Single-cell omics technologies have transformed molecular profiling by enabling high-resolution insights into cellular heterogeneity and complexity. Traditional bulk omics approaches average signals from heterogeneous cell populations, obscuring important cellular nuances. Single-cell omics studies allow the analysis of individual cells, revealing diverse cell types, dynamic cellular states, and rare cell populations. These techniques offer unprecedented resolution and sensitivity, enabling researchers to unravel the molecular landscape of individual cells. The integration of multimodal omics data within a single cell provides a comprehensive view of cellular processes, facilitating the elucidation of complex interactions, regulatory networks, and molecular mechanisms. This review discusses recent advances in single-cell and multimodal omics for high-resolution molecular profiling, highlighting the strengths and limitations of different techniques. Case studies demonstrate the applications of single-cell and multimodal omics in various fields, including developmental biology, neurobiology, cancer research, immunology, and precision medicine. Single-cell isolation and barcoding are crucial steps in single-cell sequencing workflows. Techniques such as magnetic-activated cell sorting (MACS), fluorescence-activated cell sorting (FACS), and microfluidic technologies enable the isolation and analysis of large populations of cells. Cell barcoding allows libraries from multiple individual cells to be sequenced together in a single pool, enabling efficient sequencing while preserving cell identity for downstream analysis. Single-cell genomics provides insights into genetic variants at the individual cell level. However, the small amount of DNA obtained from a single cell poses challenges for amplification and analysis. Whole-genome amplification (WGA) technologies have been developed to amplify fragments of the entire genome of a single cell while minimizing amplification errors. Recent methods such as primary template-directed amplification (PTA) and multiplexed end-tagging amplification of complementary strands (META-CS) offer improved accuracy and uniformity in single-cell genome analysis. Single-cell transcriptomics enables the characterization of cells at the single-cell and spatiotemporal levels. Recent advances in single-cell RNA-seq have enabled the establishment of diverse projects, such as the Human Cell Atlas. Various methods, including CEL-seq2, MARS-seq2.0, and SMART-seq3, have been developed to improve read mapping percentages and sensitivity while reducing bias. Long-read sequencing-based methods such as MAS-ISO-seq and SnISOr-seq address the limitations of short-read sequencing-based methods and offer improved capabilities for characterizing longer transcripts and transcript isoforms. Single-cell proteomics provides insights into the diversity of proteins within a cell population and important insights into cellular functions, disease mechanisms, and developmental processes. Mass spectrometry (MS) allows researchers to identify and quantify proteins based on their mass-to-charge ratios. Techniques such as matrix-assisted laser desorption/ionization (MALDI) and laser ablation electrospray ionization (LAESI) are commonly used for single-cell protein sequencing. Fluorescence-based methods, such as single-cell western blotting (scSingle-cell omics technologies have transformed molecular profiling by enabling high-resolution insights into cellular heterogeneity and complexity. Traditional bulk omics approaches average signals from heterogeneous cell populations, obscuring important cellular nuances. Single-cell omics studies allow the analysis of individual cells, revealing diverse cell types, dynamic cellular states, and rare cell populations. These techniques offer unprecedented resolution and sensitivity, enabling researchers to unravel the molecular landscape of individual cells. The integration of multimodal omics data within a single cell provides a comprehensive view of cellular processes, facilitating the elucidation of complex interactions, regulatory networks, and molecular mechanisms. This review discusses recent advances in single-cell and multimodal omics for high-resolution molecular profiling, highlighting the strengths and limitations of different techniques. Case studies demonstrate the applications of single-cell and multimodal omics in various fields, including developmental biology, neurobiology, cancer research, immunology, and precision medicine. Single-cell isolation and barcoding are crucial steps in single-cell sequencing workflows. Techniques such as magnetic-activated cell sorting (MACS), fluorescence-activated cell sorting (FACS), and microfluidic technologies enable the isolation and analysis of large populations of cells. Cell barcoding allows libraries from multiple individual cells to be sequenced together in a single pool, enabling efficient sequencing while preserving cell identity for downstream analysis. Single-cell genomics provides insights into genetic variants at the individual cell level. However, the small amount of DNA obtained from a single cell poses challenges for amplification and analysis. Whole-genome amplification (WGA) technologies have been developed to amplify fragments of the entire genome of a single cell while minimizing amplification errors. Recent methods such as primary template-directed amplification (PTA) and multiplexed end-tagging amplification of complementary strands (META-CS) offer improved accuracy and uniformity in single-cell genome analysis. Single-cell transcriptomics enables the characterization of cells at the single-cell and spatiotemporal levels. Recent advances in single-cell RNA-seq have enabled the establishment of diverse projects, such as the Human Cell Atlas. Various methods, including CEL-seq2, MARS-seq2.0, and SMART-seq3, have been developed to improve read mapping percentages and sensitivity while reducing bias. Long-read sequencing-based methods such as MAS-ISO-seq and SnISOr-seq address the limitations of short-read sequencing-based methods and offer improved capabilities for characterizing longer transcripts and transcript isoforms. Single-cell proteomics provides insights into the diversity of proteins within a cell population and important insights into cellular functions, disease mechanisms, and developmental processes. Mass spectrometry (MS) allows researchers to identify and quantify proteins based on their mass-to-charge ratios. Techniques such as matrix-assisted laser desorption/ionization (MALDI) and laser ablation electrospray ionization (LAESI) are commonly used for single-cell protein sequencing. Fluorescence-based methods, such as single-cell western blotting (sc