The photofragmentation spectrum of the weakly bound Sr+Ar is measured over the 418–448 nm wavelength region. Two vibrational progressions are observed and are attributed to transitions from the X2 Σ1/2 electronic ground state to vibrational levels of the excited A 2Π1/2 and A 2Π3/2 states. Isotope-resolved measurements of several of the observed transitions are performed to obtain the absolute vibrational numbering. From these, the spectroscopic constants of the involved states are deduced. We obtain ωe′=120.8 cm−1, ωeχe′=1.67 cm−1, and D0′=2303±232 cm−1 for the A 2Π1/2 state and ωe′=122 cm−1, ωeχe′=1.6 cm−1, and D0′=2575±256 cm−1 for the A 2Π3/2 state. For the ground X 2Σ1/2 state the observed hot bands yield ΔG1/2″=48 cm−1. Furthermore a value of 803±244 cm−1 is estimated for D0″. Finally the potential constants are compared with pseudopotential calculations from literature and the trends of binding energies for group II cation–argon complexes are discussed.