Cutting tool holder, cutting tool, and method of manufacturing machined product using them

A cutting tool holder may include an upper surface; a first side surface; a second side surface adjacent to the first side surface; a pocket opening into the upper surface, the first side surface, and the second side surface; a first portion located lower than the pocket and protruded outward from the first side surface; and a flow path including an inflow port and an outflow port. The first side surface may include a first recess. The flow path may include a first outflow port opening into the first portion as the outflow port and a first flow path extending from the first outflow port into the holder. The first outflow port is located at a region of the first portion corresponding to the first recess.