"I believe we possess a squad with great potential and the hunger to do well, complimented by an ardent fan base always backing us. I can't wait to get started."
Last month, Chennaiyin had sacked its head coach John Gregory following a poor run in the ongoing season of the ISL.
A Scot by birth and an Irishman by descent, Coyle has scored more than 300 goals in his entire playing career and has also appeared at the international level with the Republic of Ireland.
Coyle's journey with Chennaiyin begins with a challenging trip to Jamshedpur FC on December 9 at the JRD Tata Sports Complex.