There is provided a plasticizing device including a rotor which rotates around a rotational axis, and has a groove forming surface provided with a groove, a barrel which is opposed to the groove forming surface, and has a communication hole, and a first heating section configured to heat a material fed between the rotor and the barrel, wherein the material fed between the rotor and the barrel is plasticized and discharged from the communication hole due to a rotation of the rotor and heating by the first heating section. In the plasticizing device, the first heating section includes a first portion configured to house a first heat source, includes a second portion which is disposed closer to the groove forming surface than the first portion in an axial direction of the rotational axis, and which has a shape surrounding the communication hole when viewed along the axial direction, and is configured so that heat by the first heat source is transferred to the material between the rotor and the barrel via the second portion.