李子雄喺1977年畢業於中華基督教會基新中學（中五）。之後入咗第11期無綫電視藝員訓練班（1982年），同期畢業嘅藝員包括有梁朝偉、吳鎮宇、張兆輝等等。1985年獲邀去徐克嘅電影工作室試鏡，拍攝廣告而被發掘，成為旗下演員。1986年正式開始佢嘅電影事業，憑第一部電影《英雄本色》喺1987年攞到香港電影金像獎「最佳新人獎」、「最佳男配角獎」提名，同時提名臺灣金馬獎「最佳男配角」；佢喺戲入面多擔當反派或配角，其中喺《英雄本色》所飾演嘅反派人物「大哥成」（譚成）較出名。之後幾年佢經常都出現喺電影中，包括《倩女幽魂II人間道》、《跛豪》、《四大探長》等等，而喺《城市特警》、《喋血街頭》、《老貓》則更擔任主角。1992年，李參演三級片《性奴》，但係票房麻麻。
Lee graduated from CCC Kei Sun Secondary School (Secondary 5) in 1977. After that, he entered the 11th TVB Artist Training Class (1982), and the artists who graduated during the same period included Tony Leung, Wu Zhenyu, Zhang Zhaohui and so on. In 1985, he was invited to audition for Tsui Hark's film studio, filmed commercials and was discovered, and became his actor. He officially started his film career in 1986, and was nominated for the "Best Newcomer Award" and "Best Supporting Actor Award" at the Hong Kong Film Awards in 1987 with his first film "True Colors of Heroes", and was nominated for "Best Supporting Actor" at the Taiwan Golden Horse Awards; He mostly plays villains or supporting roles in movies, among which the villain "Big Brother Cheng" (Tan Cheng) played in "True Colors of Heroes" is more famous. In the following years, he often appeared in movies, including "A Chinese Ghost Story II: The Way of the World", "Lame Hao", "The Four Detectives", etc., and played the leading role in "City Special Police", "Bloody Street", and "Old Cat". In 1992, Li participated in the tertiary film "Sex Slave", but the box office was average.