Drug degradation products are a type of drug impurity which affects the safety of the drug products. Trazodone (TZD) is an antidepressant drug subjected to forced degradation as per ICH embedded guidelines for predicting the drug degradation products. It undergoes degradation in acidic hydrolysis, peroxide induced oxidation and upon exposure to day light and results in the formation of ten degradation products (DPs). A UHPLC method was developed to separate TZD and its DPs using the stationary phase of an Acquity UPLC CSH C₁₈ column (100 × 2.1 mm, 1.7 μm) and a mobile phase of solvent-A (10 mM ammonium acetate, pH 8.5) and solvent-B (methanol) at a flow rate of 0.25 mL min⁻¹ in gradient elution. This method was transferred to a quadrupole time-of-flight tandem mass spectrometer (QTOF-MS/MS) for identification of the DPs. Very interestingly, four dimer DPs were found under photolytic degradation conditions and they are found to be isomers. The major isomer (DP-10) was isolated by using preparative HPLC and its structure was identified using proton and carbon NMR. Three N-oxide DPs were also observed and the site of N-oxidation was identified by using atmospheric pressure chemical ionization mass spectrometry (APCI-MS). The developed UHPLC method was validated as described in the ICH prescribed guidelines and USP general chapter on method validation. The proposed validated stability indicating assay method can be used for identification and quantification of TZD and its DPs in a quality control lab for product release testing and stability studies of the drug in much less time with greater selectivity.