Let Ω ⊂ R n+1 , n ≥ 1, be a bounded open and connected set satisfying the corkscrew condition. Assume also that its boundary ∂Ω is uniformly n-rectifiable and its measure theoretic boundary agrees with its topological boundary up to a set of n-dimensional Hausdorff measure zero. In this paper we study the equivalence between the solvability of (D p ′ ), the Dirichlet problem for the Laplacian with boundary data in L p ′ (∂Ω), and (Rp) (resp. ( Rp)), the regularity problem for the Laplacian with boundary data in the Hajłasz Sobolev space W 1,p (∂Ω) (resp. W 1,p (∂Ω), the usual Sobolev space in terms of the tangential derivative), where p ∈ (1, 2 + ε) and 1/p + 1/p ′ = 1. In particular, we show that if (D p ′ ) is solvable then so is (Rp), while in the opposite direction, solvability of ( Rp) implies solvability of (Ds), for all s > p ′ . Under additional geometric assumptions (two-sided local John condition or weak Poincare inequality on the boundary), we show that (D p ′ ) ⇒ ( Rp) and (Rp) ⇒ (Ds), for all s > p ′ . In particular, our results show that in chord-arc domains (resp. two-sided chord-arc domains), there exists p0 ∈ (1, 2 + ε) so that (Rp 0 ) (resp. ( Rp 0 )) is solvable. We also provide a counterexample of a chord-arc domain Ω0 ⊂ R n+1 , n ≥ 3, so that ( Rp) is not solvable for any p ∈ [1, ∞).