To provide an imaging unit, an imaging module, and an endoscope having excellent connection reliability while achieving a reduced diameter. The imaging unit 10 according to the present invention includes a prism 40 for condensing light, a semiconductor package 20 including an image sensor 21 and having a connection electrode formed on the back surface, a plurality of cables 60a and 60b, a plurality of electronic components 51 and 52, and a multi-layer substrate 30 having a rectangular plate shape and including, on a front surface, a first electrode and a second electrode arranged side-by-side with each other and including, on a back surface f4, third electrodes 32a and 32b on which the electronic components 51 and 52 are mounted. The multi-layer substrate 30 includes walls 33-1 and 33-2 on at least two opposing sides of the back surface f4, and the semiconductor package 20 is disposed such that a light receiving surface of the image sensor 21 is arranged horizontally.
