A system for cooling a fuel injector extending into a combustion gas flow field includes a liner that defines a combustion gas flow path within a combustor and a fuel injector that extends through the liner. The fuel injector includes a main body having an annular first portion that extends outward from the liner and a second portion that extends from the first portion inward into the combustion gas flow path. The main body defines a cooling channel that is fully circumscribed within the main body and that extends between the first portion and the second portion. A cooling air inlet is defined within the annular first portion and is in fluid communication with the cooling channel. A cooling air outlet is in fluid communication with the cooling channel and is defined within the second portion downstream from the cooling air inlet.