Potato (Solanum tuberosum L.) is one of the most significant vegetable crops for humans along with corn, wheat, and rice. In this study, quantitative analysis of phenolic compounds was carried out for 21 promising potato clones and three commercial cultivars. LC–MS/MS was used for the chemical analyses. The TOGU 3/518 clone had the highest level of 4-hydroxybenzoic acid as 138.51 ± 7.35 µg/kg. TOGU 12/29 and TOGU 2/198 clones, on the other hand, had 126.24 ± 2.29 and 125.29 ± 2.74 µg/kg of 4-hydroxybenzoic acid, respectively. Salicylic acid which is a pharmaceutically significant compound was found in TOGU 3/518 clone (125.66 ± 11.51 µg/kg) as a major product. This compound was also found in TOGU 2/198 (111.27 ±1.31 µg/kg) and TOGU 12/29 clones (111.07 ± 3.68 µg/kg) as the third and fourth most abundant. In terms of caffeic acid, TOGU 3/110 clone contained the highest level (42.50 ± 3.73 µg/kg). While TOGU 7/146 clone included the most protocatechuic acid (53.98 ± 1.47 µg/kg), TOGU 3/480 clone consisted of most gentisic acid (30.79 ± 0.51 µg/kg). Quercetin, an important flavonoid found many aromatic and medicinal plants, was highest in TOGU 12/29 clone (6.27 ± 0.15 µg/kg).