紐約大學音樂劇創作碩士。憑音樂劇《Heading East》獲美國 Richard Rodgers Development Award，並為倫敦 Theatre Royal Stratford East 撰寫音樂劇《Takeaway》及廣州大劇院撰寫音樂劇《雄獅少年》。憑粵語音樂劇《四川好人》，《白蛇新傳》，《頂頭鎚》、《一屋寶貝》、《大殉情》、《奮青樂與路》、《穿Kenzo的女人》及《大狀王》等十度獲香港戲劇協會舞台劇獎。

曾為張學友音樂劇《雪狼湖》國語版出任音樂總監，《學友光年世界巡迴演唱會》及《張學友1／2世紀演場會》譜寫音樂劇環節。為任白基金粵劇《帝女花》、《再世紅梅記》及《蝶影紅梨記》譜寫新音樂。2010年為香港藝術節及毛俊輝戲劇計劃的《情話紫釵》作曲， 2014年爲舞台劇《杜老誌》作曲，及爲慶祝澳門文化中心十五周年撰寫音樂劇《我要高八度》。2014及2016年兩度與指揮家葉詠詩與香港小交響樂團合作演出《一屋寶貝》音樂廳，開創香港音樂劇音樂會先河，並於2018-2019出任小交響樂團的駐團藝術家。2020及2021策劃本土原創音樂劇音樂會《我們的音樂劇》並擔任音樂總監， 2022年與流行歌手李幸倪及爵士樂歌手塔莉•莫蓮合作，為香港法國五月《星光之城》任藝術及音樂總監。

電影方面，憑《如果．愛》先後獲台灣金馬獎、香港電影金像獎、亞太影展及香港金紫荊的最佳歌曲及音樂。為《大上海》創作的主題曲《定風波》獲第32屆香港電影金像獎最佳原創電影歌曲。參與《投名狀》配樂獲提名金馬獎及香港金像獎最佳原創電影音樂。憑《捉妖記2》配樂獲美國ASCAP Screen Music Award。其他配樂作品包括《老港正傳》、《大魔術師》、《魔警》、《親愛的》及《捉妖記》等。2018年舉行香港首個配樂師大型專場音樂會《高世章的神奇電影畫布》。

音樂以外，於2010年舉辦了香港首個古董香水瓶展覽《尋香記》，將古董香水瓶與戲劇兩種藝術共冶一爐。

Leon received a Master’s degree in Musical Theatre Writing from Tisch School of the Arts at New York University. His musical Heading East won a Richard Rodgers Development Award in the U.S. His musical Takeaway, the first major British Chinese musical in the UK, premiered at the Theatre Royal Stratford East in London in 2011, and his musical I Am What I Am premiered at Guangzhou Opera House in 2023. His Cantonese musicals, The Good Person of Szechwan, The Legend of White Snake, Field of Dreams, The Passage Beyond, Our Immortal Cantata, Sing Out and The Woman in Kenzo won ten Best Music awards at the Hong Kong Theatre Awards.

Ko was the musical director of Hong Kong pop legend Jacky Cheung’s 2004 world tour of Snow, Wolf, Lake, and put together the musical sequences in The Year of Jacky Cheung World Tour concert in 2007 and ½ Century Tour in 2011-12. He wrote new music for the classic Cantonese operas Princess Chang-ping (2006), The Reincarnation of the Red Plum Blossom (2014) and Shade of Butterfly and Red Pear Blossom (2017). Leon wrote music for the play The Liaisons for the Hong Kong Arts Festival and Fredric Mao Theatre Project in 2010. In 2014, he wrote music for the play Tonnochy, and a musical Sing High to celebrate the 15th anniversary of the Macao Cultural Centre. Leon collaborated with renowned conductor Ms. Yip Wing-sie and Hong Kong Sinfonietta on The Passage Beyond In Concert in 2014 and 2016, the first musical-in-concert in Hong Kong. With Lee Hysan Foundation, Leon wrote Sing Out – a musical for high school kids in 2017 and won Best Production at the Hong Kong Theatre Awards. Leon was the curator and musical director of The Originals, a concert to celebrate 50 years of Hong Kong original musicals. He was artistic and musical director of Cities of Light with singers Gin Lee and Talie Monin for French May 2022.

His music in the film Perhaps Love garnered a Golden Horse Award in Taiwan and a Hong Kong Film Award. He won Best Original Song at the 32nd Hong Kong Film Awards for the title song in the movie The Last Tycoon. He was nominated for Best Original Score again in 2008 for his work in the movie Warlords. He received an ASCAP Screen Music Award for the movie Monster Hunt 2 in the U.S. Other film scores include Mr. Cinema, The Great Magician, That Demon Within, Dearest and Monster Hunt. Leon held The Amazing Filmphony, a concert of his film music and songs in 2018.

Besides music, he launched Time In A Bottle, the first-ever perfume bottle exhibition in Hong Kong in 2010, showcasing the artistry of vintage bottles in the context of theatre.