Steady flowfields describing respectively the distinguished structure for subsonic, sonic, and supersonic leading-edge flow about a thin delta wing at angle of attack in a supersonic freestream are calculated numerically. Solutions of the steady three-dimensional compressible laminar Navier-Stokes equations are obtained by time integration. Details of these solutions demonstrate that the essential physical behavior of such flows, including both primary and secondary vortex motions, has been simulated. For purposes of comparison, a corresponding inviscid numerical solution was generated for the case of a subsonic leading edge. It is shown that, although the secondary features are absent, the gross dominant characteristics of the flowfield have been reproduced by the Euler equations. Effects of turbulence are assessed by incorporating a simple closure model in the viscous computation. Comparison between the numerical solutions and experimental data is provided for all flow regimes.