Thooku Thooki is a 1954 Indian Tamil-language historical drama film directed by R. M. Krishnaswami.
The film stars Sivaji Ganesan as Sundarangathan, alongside Lalitha and Padmini.
The plot revolves around the King of Sundarapuri advising his three sons to engage in business ventures to save their nation's economy.
Sundarangathan is portrayed as the brightest son, while the other two are dimwitted. All three brothers venture out of Sundarapuri for business.
Sundarangathan also visits a research centre and listens to something before embarking on his adventures.
The film is based on the play of the same name by Udumalai Narayana Kavi and was released on August 26, 1954.