Pooradam Thirunal Sethu Lakshmi Bayi CI was the monarch, though designated as the Regent due to British policy, of the Kingdom of Travancore in southern India between 1924 and 1931. She, along with her younger cousin, Moolam Thirunal Sethu Parvathi Bayi, were adopted into the Travancore Royal Family and were the granddaughters of the celebrated painter, Raja Ravi Varma.
In 1924, Maharajah Moolam Thirunal died and his grand nephew and the heir to the throne, Sree Chithira Thirunal, was just 12 years old then. A regency became necessary, since the Maharajah was still a minor. Since Travancore royal family followed the matrilineal system, Sethu Lakshmi Bayi was the head of the family. It was decided, despite the opposition of the minor Maharajah's mother, Junior Maharani Sethu Parvathi Bayi, that Sethu Lakshmi Bayi should be Regent as she was the Senior Maharani until the minor King came of age in 1930. She was an absolute monarch in her own right as per matrilineal law and ruled as the sovereign.