Molecular-level investigation of crude oil has become an essential part of oil spill research, It facilitates the assessment of oil behavior, fate, impacts, as well as the evaluation of oil spill origins, toxic substances, and the effect of such incidents. Notable oil spill incidents, such as the Deepwater Horizon, have emphasized the need for molecular-level information on spilled oil to evaluate and monitor environmental damage. In this study, the term 'Environmental Petroleomics' is defined. During the weathering of spilled oil, various effects can alter the oil's chemical composition, including evaporation, dispersion, photo-oxidation, and microbial degradation. The major toxic compounds in the spilled oil are aromatic compounds, followed by polar oxygenated aromatic compounds. Although gas chromatography-mass spectrometry (GC-MS) is an effective approach for compositional analysis of crude oil, it falls short in its ability to separate individual compounds in the weathered oil. This is particularly challenging when dealing with weathered oil enriched with polar oxygen- and sulfur-containing compounds that emerge during the weathering process . Ultra-high-resolution mass spectrometry (UHR-MS) has played a key role in the development of Environmental Petroleomics, proving effective in characterizing various polar species. This review explores the application of ultra-high-resolution mass spectrometry for oil spill research. The study concludes that the toxicity of weathered crude oils results from the photo-oxidation of crude oil molecules into highly oxygenated, water-soluble species. Prospective research in environmental petroleomics concerning the analysis of oil spills may direct its attention towards innovating novel methodologies. These could encompass high-resolution imaging of oil spills, time-resolved analysis of spill dynamics, integration of ultra-high-resolution mass spectrometry (UHR-MS) with complementary techniques, and the utilization of UHR-MS for biomarker analysis.