A tamper-evident dispensing spout is configured for use on single-serve cartons, such as paper-based gable-topped cartons. The spout structure includes a spout body having a generally cylindrical wall portion, and a mounting flange extending outwardly from one end of the wall portion. The spout body defines a dispensing opening generally opposite the flange portion, with an opening member hingedly mounted on the spout body for movement from a first, sealed position, to a second, opened position for consumption of the container's contents. The opening member preferably includes a locking element so that the opening member is conveniently retained in its opened position during use.