Provided are an imaging unit, an imaging module, and an endoscope capable of mounting a plurality of electronic components with high accuracy and simplicity while achieving miniaturization. The imaging unit 10 according to the present invention includes a semiconductor package 20, a circuit board 30, electronic components 51 and 52, and a plurality of cables 60a to 60c. The circuit board 30 includes a main body 31 and an attachment portion 32. A connection land is formed on the main body 31. The attachment portion 32 protrudes on the back surface of the main body 31 and includes cable connection electrodes formed on at least two opposing side surfaces among protruding side surfaces. The attachment portion 31 protrudes from the main body 31 such that a center plane a1 of two side surfaces on which the cable connection electrodes are formed to oppose each other is shifted from a center plane a2 of side surfaces parallel to the two side surfaces of the attachment portion 32 of the semiconductor package 20, and at least one side surface is perpendicular to the back surface of the main body 31 and has a step shape. An electrical component mounting area R is arranged on the back surface of the main body 31 side-by-side with the attachment portion 32.
