Thai Ullam

Thai Ullam
Tamil	தாய் உள்ளம்
Directed by	K. Ramnoth
Based on	East Lynne by Henry Wood
Starring	R. S. Manohar Gemini Ganesan
Production company	Narayanan & Company
Release date	1952 (1952)
Country	India
Language	Tamil

Thai Ullam (English: Mother's Heart) is a 1952 Indian Tamil-language film directed by K. Ramnoth. Starring R. S. Manohar and Gemini Ganesan in the lead roles, the film has music composed by V. Nagaiah and A. Rama Rao. It is an adaptation of the English tearjerker novel East Lynne, by Henry Wood.

K. Ramnoth, who had left Gemini Studios on 15 August 1947, worked for Narayanan & Company, for which he made the film Thai Ullam, an adaptation of the novel East Lynne by Henry Wood. While R. S. Manohar was cast as the male lead, T. S. Balaiah was considered for playing the antagonist. He however opted out of the project after demanding a salary of ₹75,000, which he was refused. Subsequently, he was replaced by a then struggling actor named R. Ganesh, who later became known as Gemini Ganesan. The film became a major breakthrough for Ganesan, who would later become a part of the "Big Three" of Tamil cinema, the other two being Sivaji Ganesan and M. G. Ramachandran.

The songs were composed by Nagaiah and A. Rama Rao, with lyrics by Kanakasurabhi.

Film historian Randor Guy called Thai Ullam a "cinematic masterpiece", and concluded that the film would be "Remembered for: melodious music, especially hit tunes by the inimitable MLV."