A cutting insert according to an embodiment of the present invention includes an upper surface, a side surface, and a first cutting edge located at an intersection of the upper surface and the side surface. The upper surface includes a pair of raised parts located opposite to each other with a perpendicular bisector of the first cutting edge interposed therebetween. A top of each of the pair of raised parts includes at least two protrusions oriented toward a direction along the perpendicular bisector in a top view. Each of the at least two protrusions includes a first protrusion located on a side closest to the perpendicular bisector, and a second protrusion which is located on a side further away from the perpendicular bisector than the first protrusion, and is located at a higher position than the first protrusion. A cutting tool including the cutting insert, and a method of manufacturing a machined product by using the cutting tool are also provided.