An object is to provide a floating bush bearing device with excellent oscillation stability and small bearing loss. A floating bush bearing device which rotatably supports a rotation shaft includes: a bearing housing, a floating bush rotatably disposed between the rotation shaft and an inner circumferential surface of the bearing housing, in the bearing housing, and a bush side oil supply hole which is formed through the floating bush and is capable of supplying lubricating oil between the rotation shaft and the inner circumferential surface of the floating bush, the inner circumferential surface of the floating bush has a non-circular shape so that a gap portion is formed between the rotation shaft and the inner circumferential surface of the floating bush, the gap portion having a predetermined clearance or larger regardless of relative positions of the rotation shaft and the inner circumferential surface of the floating bush, and the bush side oil supply hole communicates with the gap portion.