A dual-channel optical navigation system with vertically aligned sensors. The dual-channel optical navigation system includes a circuit board, a contact navigation sensor, and a free-space navigation sensor. The circuit board mechanically supports and electrically connects multiple navigation sensors on opposing sides of the circuit board. The contact navigation sensor is coupled to a first side of the circuit board. The contact navigation sensor generates a contact navigation signal based on contact navigation images of a contact navigation surface approximately adjacent to the dual-channel optical navigation system. The free-space navigation sensor is coupled to a second side of the circuit board. The free-space navigation sensor generates a free-space navigation signal based on free-space navigation images of an operating environment of the dual-channel optical navigation system.