Postharvest fungal spoilage and storage contamination remain major causes of quality loss and food safety concern in fresh commodities and stored grains. Early detection is often difficult because infections may remain latent or asymptomatic until deterioration is advanced. Volatile organic compound (VOC)-based sensing offers a rapid and non-destructive tool to monitor infection-related changes in the headspace and to support timely decisions along the postharvest chain. This Scopus-based systematic review synthesises evidence published between 2011 and 2026 on VOC-based sensing and related proxy approaches for early detection, monitoring, screening, and decision support in postharvest fungal spoilage and storage contamination in fruit systems and cereals or grains, with a specific focus on deployment readiness and decision-support applications. The Scopus search identified 192 records. After deduplication, screening, and eligibility assessment, 61 studies were included in the synthesis. The reviewed literature shows that electronic nose systems and sensor arrays are mainly used for rapid screening and triage, while gas chromatography–ion mobility spectrometry (GC-IMS) and headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS) are more often applied to storage monitoring and contamination staging. Headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) remains central for marker discovery and interpretation, whereas fast mass spectrometry (MS), optical arrays, and biosensor-based approaches address more specific deployment constraints. Across studies, the strongest evidence supports VOC-based sensing as a screening layer rather than a standalone diagnostic method. The main barriers to routine implementation are limited external validation, incomplete control of biological and storage-related confounders, sensor drift, and insufficient standardisation of sampling and reporting. Future research should prioritise multi-lot and multi-site validation, quantitative endpoint anchoring, calibration transfer, and decision thresholds linked to operational consequences. Overall, VOC-based sensing can support food control strategies by enabling earlier risk recognition, lot prioritisation, and targeted confirmatory testing.