Flow path assemblies of gas turbine engines are provided. For example, a flow path assembly comprises an inner wall and a unitary outer wall that includes a combustor portion extending through a combustion section of the gas turbine engine and a turbine portion extending through at least a first turbine stage of a turbine section of the gas turbine engine. The combustor portion and the turbine portion are integrally formed as a single unitary structure. The flow path assembly further comprises a plurality of nozzle airfoils, each nozzle airfoil having an inner end radially opposite an outer end. The inner wall or the unitary outer wall defines a plurality of openings therethrough, and each opening is configured for receipt of one of the plurality of nozzle airfoils. Methods of assembling flow path assemblies also are provided.