Emerging liquid biopsy platforms are expanding frontiers in lung cancer care, facilitating real-time molecular insights and addressing some of the limitations of tissue biopsy. While standardization and sensitivity improvements are undergoing continuous refinement in those liquid biopsy techniques that are now established, several advancements are expanding the panorama of its potential future applications. This review offers an overview of the emerging uses of liquid biopsy in the field of lung cancer, with a specific focus on emerging technologies. We comprehensively reviewed the literature through PubMed and Embase, combining keywords and Medical Subject Headings (MeSH) related to small-cell (SCLC) and non-small-cell lung cancer (NSCLC) and liquid biopsy using Boolean operators. The search was limited to publications from 2017 up to 2026. Titles and abstracts underwent manual scrutiny for relevance. We critically analyzed a body of evidence assessing the potential role of liquid biopsy in common and uncommon applications, such as its combination with machine learning and AI and its integration in multiomics approaches or its usage in next-generation technologies—including label-free CTC isolation, DNA fragmentomics and end-motif profiling, four-dimensional proteomics, and unconventional biospecimens—that remain largely unaddressed in prior narrative reviews on this topic.