Thiri Pyanchi Yin May FRCS FRCP FRCOG (Burmese: ရင်မေ, pronounced [jìɰ̃ mè]; September 1900 – 29 September 1978) was a Burmese physician and educator. She was the first Burmese obstetrician and gynecologist, and the first person to perform the Caesarian section in British Burma. She is also known for her research on amoebic vaginitis, known as May's disease.