The upper critical field Hc2 of optimally doped iron-based superconductor SrFe2(As1−xPx)2 (x = 0.35, Tc = 25 K) was measured as a function of temperature down to 1.6 K for two principal directions of magnetic field H c and H a. Measurements were performed in pulsed magnetic fields up to 65 T using a tunnel-diode resonator technique on as-grown and heavy-ion irradiated single crystals, with columnar defect density corresponding to a matching field Bφ = 25 T. The Hc2,c(T ) is close to T -linear, while clear saturation is observed for Hc2,a(T ), leading to a strongly temperature dependent anisotropy parameter γ. The linear shape of Hc2,c(T ) is very similar to that observed in nodal KFe2As2 but very different from full-gap LiFeAs. Irradiation does not introduce any additional features on Hc2(T ) line corresponding to the matching field. Instead, it suppresses uniformly both Tc and Hc2, keeping their ratio constant.