We obtain sharp local C 1,α regularity of solutions for singular obstacle problems, Euler-Lagrange equation of which is given byfor 0 < γ < 1 and p ≥ 2. At the free boundary ∂{u > ϕ}, we prove optimal C 1,τ regularity of solutions, with τ given explicitly in terms of p, γ and smoothness of ϕ, which is new even in the linear setting.