Several Achillea species have been reported to exhibit cytotoxic, wound-healing, antioxidant, and antibacterial activities. In this study, the phytochemical composition of aqueous ethanol extracts from ten Achillea taxa was investigated using LC–MS/MS analysis. The antioxidant potential of the extracts was evaluated, and their inhibitory effects on acetylcholinesterase, butyrylcholinesterase, tyrosinase, α-glucosidase, and α-amylase enzymes were assessed. Quinic acid (11.95–43.93 µg/mg), chlorogenic acid (9.82–32.75 µg/mg), cynaroside (9.82–32.75 µg/mg), and rutin (0.56–21.11 µg/mg) were identified as the major compounds. Among the tested species, Achillea teretifolia exhibited the strongest antioxidant activity in ABTS and DPPH assays, with IC50 values of 231.5 ± 0.72 and 11.31 ± 0.25 µg/mL, respectively. In contrast, Achillea lycaonica showed the most potent tyrosinase inhibition (IC50: 1.83 ± 0.26 µg/mL). The extracts also demonstrated inhibitory activity against α-amylase and α-glucosidase, with IC50 values ranging from 0.39 to 195.8 mg/mL and 0.19 to 39.18 µg/mL, respectively. Furthermore, molecular docking studies using AutoDock Vina and ChemOffice explored the interactions of quinic acid, the predominant phenolic compound, with tyrosinase, α-amylase, and α-glucosidase.