A lens unit for an endoscope includes: a lens holding frame provided with a through hole extending from a distal end side to a proximal end side; a convex portion; a first lens including a first portion arranged on the distal end side, and a second portion whose outside edge forms a step portion to which the convex portion is housed; and a second lens arranged near the distal end side. The second lens is positioned closer to the proximal end than an end portion of the lens holding frame on the distal end side in a first state where the second portion is arranged closer to the proximal end than the first portion. At least a part of the second lens protrudes from the end portion in a second state where the first portion is arranged closer to the proximal end than the second portion.