Production of hydrocarbon fuel from waste oil such as industrial and engine waste oil is an excellent way for producing alternating fuel sources. The aim of the present study is to obtain diesel-like fuel from waste engine oil (WEO) which can be used as an alternate fuel for compression ignition (CI) engine. With this aim in mind, WEO was purified from contaminants and thermally cracked with two different catalysts such as red mud and fly ash in a catalytic thermal reactor (CTR). The oil product obtained after catalytic conversion using red mud catalyst was named as WEORM and using fly ash catalyst was named as WEOFA. To investigate the influence of these two catalysts with WEO, different properties such as density, kinematic viscosity, calorific value, flash, and fire points were determined. Moreover, the compositional analyses for WEORM and WEOFA were analyzed by Fourier transform infrared (FT-IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS). FT-IR spectroscopy revealed the presence of several bonds which appeared in WEORM and WEOFA were almost identical to the diesel fuel. Further FT-IR results confirmed that most of the hydrocarbons present in WEORM and WEOFA were alkanes. Furthermore, in GC-MS analysis, WEORM and WEOFA were mainly composed of C-10-C-30 hydrocarbons with the presence of aliphatic hydrocarbons and aromatics. Similar to fossil diesel fuel, they mainly contain paraffins, napthenese, and aromatics. Our results revealed that WEO can be effectively recycled and reused as an alternate source of hydrocarbon energy.