A nasal dilator device (100, 200, 300, 400, 500, 600, 700) comprising: a substantially U-shaped body including: a central portion arranged to span a septum of a nose when worn by a user; and first and second leg members (106a, 106b) extending from the central portion in a first plane; a first cantilever rib member extending outward from the U-shaped body in a second plane; a second cantilever rib member extending outward from the U-shaped body in a third plane; wherein the first and second cantilever rib members (110a, 110b) extend away from each other; a first intermediate section connecting an end of the first leg member to a proximal end of the first cantilever rib member, wherein the first intermediate section extends between the first plane and second plane; and a second intermediate section connecting an end of the second leg member to a proximal end of the second cantilever rib member, wherein the second intermediate section extends between the first plane and the third plane; wherein the first, second and third planes are different from each other, or wherein the second and third planes are the same plane and are different to the first plane, or wherein the second and third planes are converging; wherein the first and second intermediate sections are arcuate intermediate sections, each having a curvature along its length; and wherein: the first and second leg members (106a, 106b) are inclined towards each other such that a relatively greater distance is provided between the first and second leg members towards the central portion to accommodate a columella of a nose when donned by the user; the first and second intermediate sections (108a, 108b) are inclined away from each other to assist in urging the respective first and second cantilever rib members (110a, 110b) against inner walls of respective nostrils when the device is worn by the user; the first and second intermediate sections (108a, 108b) extend obtusely from the ends of the first and second leg members (106a, 106b), and wherein each of the second and third planes (P2, P3) forms an obtuse angle with the first plane; and wherein the first and second intermediate sections, in use, extend along a length of the septum and each of the first and second cantilever rib members, in use, extends from a floor of a respective nasal passage to an inner wall of the nostrils. a central portion arranged to span a septum of a nose when worn by a user; and first and second leg members (106a, 106b) extending from the central portion in a first plane; a first cantilever rib member extending outward from the U-shaped body in a second plane; a second cantilever rib member extending outward from the U-shaped body in a third plane; wherein the first and second cantilever rib members (110a, 110b) extend away from each other; a first intermediate section connecting an end of the first leg member to a proximal end of the first cantilever rib member, wherein the first intermediate section extends between the first plane and second plane; and a second intermediate section connecting an end of the second leg member to a proximal end of the second cantilever rib member, wherein the second intermediate section extends between the first plane and the third plane; wherein the first, second and third planes are different from each other, or wherein the second and third planes are the same plane and are different to the first plane, or wherein the second and third planes are converging; wherein the first and second intermediate sections are arcuate intermediate sections, each having a curvature along its length; the first and second leg members (106a, 106b) are inclined towards each other such that a relatively greater distance is provided between the first and second leg members towards the central portion to accommodate a columella of a nose when donned by the user; the first and second intermediate sections (108a, 108b) are inclined away from each other to assist in urging the respective first and second cantilever rib members (110a, 110b) against inner walls of respective nostrils when the device is worn by the user; the first and second intermediate sections (108a, 108b) extend obtusely from the ends of the first and second leg members (106a, 106b), and wherein each of the second and third planes (P2, P3) forms an obtuse angle with the first plane; and wherein the first and second intermediate sections, in use, extend along a length of the septum and each of the first and second cantilever rib members, in use, extends from a floor of a respective nasal passage to an inner wall of the nostrils.