Jason Tsai (born Tsai Ji-chun ; 17 May 1951 at Tainan County, Taiwan, is a Taiwanese founder and chairman of the Entagroup of telecommunications companies in the United Kingdom (UK); including Entatech UK Ltd, Entamedia Ltd, and Enta.net. He is also the founder of UK Telford Chinese School, and the president of The Tsai Lao-Chi Charitable Foundation in the UK.
His British-registered company Changtel was found by Her Majesty's Revenue and Customs (HMRC) to have participated in carousel fraud, as a result of which Tsai lost control of Entatech. On 8 May 2017, as the final link to that fraud, Entatech entered administration, and 50 people lost their jobs overnight. On 21 July 2017, Tsai was sentenced to imprisonment for 18 months at the High Court of Justice (Chancery Division) for Contempt of Court on account of 27 breaches of a Freezing Order.