Abstract: A fluid container lid is disclosed which includes an outer rim and a curved sealing collar coupled to the inner portion of the top rim and extending downwardly therefrom. The fluid container lid further includes an outwardly extending annular locking shoulder which is coupled to the bottom of the sealing collar. The annular shoulder includes an outwardly extending top surface which is coupled to an inwardly extending lower surface. A lid bottom is coupled to the inwardly extending lower surface. The sealing collar and the locking shoulder are adapted to engage the inside of the rim of a fluid container. The top rim of the lid further includes an outwardly extending tab for facilitating the removal of the lid from the container.