The aim of this work was to determine the optimal extraction conditions of phenolic compounds from fig (Ficus carica L.) roots using two approaches, single-factor experiment and response surface methodology (RSM), and to identify some phenolic compounds by ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS). For each studied extraction parameter, total phenolic content (TPC) and DPPH free radical scavenging activity (DPPH) were evaluated. The result of single-factor experiments showed that all extraction parameters had significant effects ( p < 0.05) on TPC and DPPH. The solvent concentration, extraction time, and temperature were studied by RSM using Box-Behnken design. RSM data analysis showed that the optimal extraction conditions were 62.66% acetone using a temperature of 45.75°C during 138.65 min with maximized values for the two responses of 23.29 mg GAE/g DW (TPC) and 46.58% (DPPH). The experimental checking of results revealed the validity of elaborated models and their suitability for the prediction of both responses. Furthermore, the analysis of the fig root extracts by UPLC-MS led to the identification of five phenolics (chlorogenic acid, rutin, isoquercetin, quercetin, and luteolin).