OctamegaminxA megaminx redesigned to have the shape of an octahedron but unlike its predecessors, it was twisted inside of its solid.
Octo StrapA face turning octahedron with the middle layer placed in midturn by 60°.
Olympic GeraniumA version of Geranium with five circles in a pattern similar to the olympic rings.
Orbit CubeA 3x3x3 with four circles on each face. These rotate with each turn in the same direction.
Orc 2x2x2A 2x2x2 remodelled after the humanoid animals from the worls of J.R.R. Tolkien.
Orlov fourThe successor of the Orlov with four gears, even with the same middle pieces.
Orlov gearInspired by the gear puzzles from Douglas Engel. Three circles and irregular center pieces.
OrpheusA hybrid of 2x2x2 and DeCETH.
Other 4x4x4 (aka Puzzle 19)Designed to be a 4x4x4 with exposed new theoretical pieces. Although it has 64 pieces it presents itself as a superset of the 3x3x3.
Padlock CubeA 3x3x3 with bars attached to two edges. This concept implements a new type of bandaging.