Sybil Medan Kathigasu GM (née Daly; 3 September 1899 – 12 June 1948) was a Malayan Eurasian nurse who supported the resistance during the Japanese occupation of Malaya.

While she was practising nursing and midwifery at the Kuala Lumpur General Hospital, Kathigasu first met Dr. Arumugam Kanapathi Pillay, a second-generation Malaysian Ceylonese, born on 17 June 1892 in Taiping to Kanapathi Pillay and Thangam, immigrants of Sri Lankan Tamil origin.

Kathigasu's first child was a son born on 26 August 1919, but due to major problems at birth, died after only 19 hours.

He was named Michael after Kathigasu's elder brother, who was born in Taiping on 12 November 1892 and later joined the British Army, and was killed in action on 10 July 1915 while taking part in the Gallipoli campaign.

74, Main Street in Papan, Kathigasu and her husband secretly kept shortwave radio sets and listened to BBC World Service broadcasts.

As she was able to speak fluent Cantonese, Kathigasu and her husband were able to quietly supply medicines, medical services and information to the resistance forces - members of 5th Independent Regiment Malayan People's Anti-Japanese Army (MPAJA).

Despite being interrogated and tortured by the Japanese military police for two years, Kathigasu and her husband persisted in their efforts and were thrown into Batu Gajah jail in Feb 1945.

It is reported that the cause of death was due to a wound on Kathigasu's jaw left by a Japanese soldier which led to fatal septicaemia.

In July 2024, the Bishop of Penang, Cardinal Sebastian Francis, announced that, in light of her outstanding example of missionary witness, he was opening a cause to examine Kathigasu's life for her possible canonization.