A medical observation apparatus includes a columnar microscope unit configured to image a minute part of an object to be observed with magnification and thereby output an imaging signal. A support unit includes a first joint unit holding the microscope unit in a rotationally movable manner around a first axis parallel to a height direction of the microscope unit, a first arm unit holding the first joint unit and extending in a direction different from the height direction of the microscope unit, a second joint unit holding the first arm unit in a rotationally movable manner around a second axis orthogonal to the first axis, and a second arm unit holding the second joint unit. In a plane passing through the first and second axes, a cross section of the microscope unit, the first and second joint units, and the first and second arm units is included in a circle that has a center at a focus position of the microscope unit and passes through an end point of the first joint unit that is at the maximum distance from the focus position.