The Archeparchy of Trichur, in Thrissur District of Central Kerala, India, with nearly half a million Syro-Malabar Catholics now, used to be the largest Catholic diocese in India when it included the Syro-Malabar Catholic Diocese of Irinjalakuda until 1978 and Syro-Malabar Catholic Eparchy of Palghat until 1973. Syro-Malabar Catholic Diocese of Irinjalakuda, also located in Thrissur District, has over a quarter million Syro-Malabar Catholics now. Syro-Malabar Catholic Diocese of Palghat in Central Kerala extends to some regions in the neighbouring state of Tamil Nadu. In 2010, the parts of Tamil Nadu under the Syro-Malabar Catholic Diocese of Palghat were separated to form another Syro-Malabar Catholic Diocese of Ramanathapuram.

The Eparchy of Irinjalakuda is a suffragan eparchy in the ecclesiastical province of the metropolitan Syro-Malabar Catholic Archeparchy of Thrissur in Kerala state's Thrissur District, southern India.It is part of the Syro-Malabar Church.