Poondi murder case was a murder trial conducted in British India between October 1911 and June 1913. The trial was a cause celebre of the early 20th century Tanjore District.
Dhanabhagyam, the daughter-in-law of Vaidyanatha Pillai, the zamindar of Poondi was murdered under mysterious circumstances in the early hours of 21 October 1911. Vaidyanatha Pillai was convicted for organising the murder and sentenced to death by the First Class Magistrate at Mannargudi. The sentence was confirmed by the District and Sessions Court at Tanjore. In June 1913, Swaminathan, the lawyer for the defendant, appealed to the Privy Council of the United Kingdom for a re-trial which was granted. The re-trial overturned Vaidyanatha Pillai's conviction and acquitted him.