Similarity solutions of the boundary‐layer equations representing the flow of jets in an external stream and tailored pressure gradients were obtained. These solutions apply to jets in coflowing and counterflowing streams. A number of analytical solutions not previously published were obtained. Of particular interest are the solutions for small‐increment jets which imply that a Gaussian velocity profile exists far downstream from the origin of the jet, even in arbitrary pressure gradient. The solutions were extended to turbulent flow using the hypothesis of a constant eddy viscosity, which in turn, was modified to account for intermittency. The theoretical predictions were compared with the measurements of Gartshore in self‐preserving wakes and the agreement between theory and experiment is good.