小半圆叶杜鹃（学名：Rhododendron thomsonii sp. lopsangianum）为杜鹃花科杜鹃属下的一个亚种。

Rhododendron thomsonii (半圆叶杜鹃) is a rhododendron species native to northern India, Bhutan, Nepal, Sikkim, and southern ****** in China, where it grows at altitudes of 3000–4000 meters. It is a shrub that grows to 2–4 m in height, with leathery leaves that are oblong-elliptic to ovate or orbicular to obovate, 3–7 by 2–6 cm in size. Flowers are red.