Enhanced mixing and transport properties are distinguishing characteristics of both turbulent and more structured complex flows. The concepts of eddy diffusion and eddy viscosity, for example, were introduced as attempts to “parameterize” these effects to produce reduced models for theoretical analysis and simulations. At the same time turbulent mixing and transport is the focus of significant attention from a fundamental point of view, based in some cases on the Navier-Stokes equations and in other cases on models or special flows amenable to more thorough analytical investigations. This workshop is concerned with modern mathematical approaches to the study of transport and mixing in turbulence and other complex flows, including transitional flows with significant attention to applications from the applied sciences, predominantly geophysics.