TrinityA Tricopter 9 Plus (with four additional non-intersecting 90°-turns) in the shape of Ice-9.
Triple TorusA 2x2x2 reduced to almost nothing mechanically but with twelve pairs of exchangable pieces at the "edges" of the 2x2x2.
TriQuadA non truncated version of Bygride-3-4 with different cuts.
TriTangleTriTangle is essentially the upper three axes of a bandaged Impossiball (aka Kilominx), with the shape of an asymmetrically flattened triangular dipyramid.
TRIvial circlesA 2D puzzle with two overlapping circles that share one of their 3 leaves.
Trivial SkewbA skewb with the additional ability to turn the corners, making the puzzle trivial.
TrixA Dino Cube redesigned from scratch into the shape of a rhombic dodecahedron.
TSI SkewbA 3D-printed skewb in the shape of a tetrahedrally stellated icosahedron, also known as a tetrahedrally diminished dodecahedron.
TumblerGently roll to get small beads to their own arms. In other words: Match the color of the beads to color of arms.
Tunnel CubeThe Handlebar Cube implemented differently. It allows more moves than the predecessor.
Turn ApartA 2x2x2 with restricted movemements that can be taken apart.
Turn FourAn enhanced but simultanuously reduced version of Rashkey.