In this work, the physicochemical and functional properties of starches isolated from four varieties of soft acorn of holm oak grown in Algeria were investigated. The obtained results showed that the levels of moisture, ash, fat, crude fiber and protein ranged from 2.2 to 15.91, 0.1 to 0.18, 0.23 to 0.63, 0.01 to 1.29% and from 0.01 to 1.05%, respectively; however the purity of starch ranged from 48.93 to 89.83% and the amylose content from 20 to 39%. Evaluation of solubility and swelling revealed low capacities in water at 90 °C; they were about 14% and 13 g/g, respectively. Holm oak starch pH values are between 4.73 and 6.43 and, in their titratable acidity between 0.27 and 0.81. The molecular weight was between 2.65 × 107 and 8.22 × 107 g/mol, gelatinization temperature ranged from 71 to 88.1 °C when gelatinization enthalpy from 11.80 to 15.46 J/g. Starch granules characterized by SEM showed that they are mostly spherical, ovoid, and sometimes hemispherical with sizes ranging from 2.5 to 24 µm. Furthermore, FT-IR analysis showed that the majority of the functional groups present OH, CH, COH and COC links. The obtained characteristics make soft acorns of holm oak as a potential source of starch for biotechnological applications.