It is demonstrated that strain‐induced electric fields in [111] growth‐axis strained‐layer structures can be used to induce a two‐dimensional electron gas without the necessity of modulation doping. A simple analytic expression is derived for the density of the two‐dimensional electron gas. The density has a simple linear relationship to the strain‐induced electric fields. The calculation predicts that two‐dimensional densities in the range 1011–1012cm−2should be easily realized in strained‐layer structures. Results are calculated for a variety of material systems.