A collapsible drinking cup assembly having a plurality of annular ring segments each flexibly coupled together, end-to-end. An upper drinking lip segment of the ring segments includes an interior and exterior sidewall such that the drinking lip segment tapers inwardly from a lower base portion to an annular upper distal edge thereof. A support floor of the cup apparatus includes an annular bottom flange extending radially beyond an exterior wall of the bottom ring segment. Atop lid member extends over an opening into the cup apparatus, and includes a pair of opposed, inner and outer contact walls that collectively define an annular receiving groove therebetween. The cup apparatus can be expanded from a collapsed position to an expanded position when both the annular bottom flange and the lid member are radially gripped and axially pulled apart longitudinally thereof before separation of the lid member from the drinking lip segment.