A modular seat assembly having an elongate support spine extending longitudinally from a first end to a second end is provided. A seat portion is connected to a front side of the support spine, and each of the seat portion and the support spine includes one of a complementary pair of interlocking portions. The interlocking portion of the seat portion slides onto the interlocking portion of the support spine over the first end. The modular seat assembly further includes an end cap lockably disposed over the first end that prevents the seat portion from sliding off the support spine.