The pyrolysis of natural rubber sludge, a significant byproduct of the rubber industry, was investigated to produce valuable energy products, including bio-oil, syngas, and biochar. This study aimed to explore the potential of converting rubber sludge into renewable fuels and chemicals using a lab-scale pyrolysis process. The natural rubber sludge was pre-treated to remove non-biodegradable fillers such as calcium carbonate (CaCO₃) using hydrochloric acid (HCl) washing and water washing. The pyrolysis process was conducted at 450 ℃ for 30 min in an anaerobic environment. The resulting bio-oil was analyzed using gas chromatography-mass spectrometry (GC-MS) to identify the key aromatic and phenolic compounds formed during pyrolysis. Major compounds detected included syringol (7.651 min), creosol (6.392 min), vanillin (8.457 min), syringyl acetone (10.772 min), eugenol derivatives (Z-isoeugenol: 9.450 min, E-isoeugenol: 12.009 min), and guaiacol (5.548 min). These compounds are typical byproducts of lignin degradation and indicate the significant presence of lignin in the rubber sludge. The bio-oil produced exhibited a high calorific value (44.47–44.68 MJ/kg), making it a promising renewable fuel, though its low flash point and high acidity suggest the need for further processing. Syngas analysis revealed high hydrogen (32.8%) and carbon monoxide (24.3%) yields, which were significantly improved by the pre-treatment process. This study demonstrates that pyrolysis of natural rubber sludge, especially with optimized pre-treatment, offers a sustainable approach to waste management while generating high-quality bio-oil and syngas for renewable energy applications. The findings highlight the viability of integrating pyrolysis into a circular economy model, offering an alternative energy solution with environmental benefits.