Quantum fluctuations in a 2D honeycomb Kitaev model completely suppress long-range order to produce a quantum spin liquid (QSL) ground state. While $α$-RuCl$_{3}$ is positioned on the verge of the Kitaev QSL phase, fragile long-range magnetic order arises from non-Kitaev terms in the Hamiltonian. In a study of Ru$_{1-x}$Ir$_{x}$Cl$_{3}$ single crystals, we find that spin vacancies in the form of nonmagnetic Ir$^{3+}$ successfully destabilize magnetic order in $α$-RuCl$_{3}$. Neutron diffraction and bulk characterization demonstrate a suppression of the primary zig-zag magnetic phase transition in Ru$_{1-x}$Ir$_{x}$Cl$_{3}$ single crystals to below 2 K by $x = 0.09$, potentially paving the way towards the sought-after pure Kitaev limit. Stacking disordered regions exhibit less sensitivity to dilution, and sustain weak zig-zag correlations to larger $x$, near the percolation threshold for the honeycomb lattice. The phase diagram as a function of $x$ and T is determined.