Historically dismissed as non-functional “junk” RNAs, non-coding RNAs have recently been acknowledged for their significant role in the pathogenesis of various cancers, overturning previous misconceptions. The past decade has not only highlighted their biological importance but also revealed frequent abnormalities in their expression levels across numerous cancers, sparking interest in their potential as cancer biomarkers. Among these, miRNAs can influence gene transcription epigenetically and are extensively researched as candidates for liquid biopsy biomarkers in cancer diagnosis. Advances in high-throughput sequencing technologies have allowed for detailed molecular profiling of non-coding RNA expression across different cancers. Moreover, innovations in technology that enable the detection of low-abundance RNAs in blood samples have led to the discovery of new, previously undetectable biomarkers for cancer. This paper provides an update on the recent advancements in using non-coding RNAs as non-invasive biomarkers for cancer, assessing various non-coding RNA types for their efficacy as blood-based markers and exploring how recent technological developments have enhanced the field of non-invasive molecular biomarkers in oncology.