Miscibility phase separation in lipid bilayers is widely implicated as an organizing principle in living cell membranes. However, the chemical and physical aspects of how membrane phase separation modulates protein activity remain obscure. Herein, we describe formation of ordered superstructures of coexisting liquid phases in bilayer membranes. Metastable stripe and hexagonal domain lattices are observed, as well as transitions between them. The high degree of order achieved by these methods facilitates statistical analysis of domain spatial distributions and enables measurement of domain interactions. Such long-range ordering principles may exist in more complicated membrane systems.