We report, for the first time, self-assembled cantilever and clamped-clamped tri-state carbon nanotube (T-CNT) nano-electro-mechanical (NEM) switches with sub-100 nm air-gap dual lateral gates. Unlike conventional bi-state CNT switches, the T-CNT NEM switches operate in three states: CNT in the center (OFF), CNT attracted to the left gate (ON-1) or to the right gate (ON-2). They demonstrate excellent sensing current windows (I-on/I-off similar to 10(7)), ultra-low I-off (similar to 10(-14)A), good isolation and high endurance (cycle>10(2)). The proposed hysteretic switches offer a complementary metal-oxide-semiconductor (CMOS) - compatible bottom-up approach for various potential applications: logic devices, memories, etc., with higher circuit density and novel ultra-scaled configurability functions.