Xu Zhengxi (Chinese: 徐正溪, born 5 May 1985), also known as Jeremy Tsui, Izz Xu, Jones Xu or Jeremy Jones Xu is a Chinese actor. He gained increased popularity with his portrayal of Yuwen Hu in the historical drama The Legend of Dugu, as well as his role as an antagonist in the period drama Siege in Fog.

He speaks Mandarin, Cantonese and English. Before his success, he suffered from hyperthyroidism but recovered.

On March 15, 2024, he announced his retirement from acting on his personal Weibo account. On September 14. In 2024, both he and his agency published statements on Weibo to explain that his decision had been triggered by the aggravation of his father’s state of health, which, as the only child, required him to manage the situation, adding that by now a satisfactory solution had been found to allow his return to acting.