In 1995, Chung was recommended by Taiwanese music producers, and signed on with the record company BMG. That July, he debuted as a singer with his first solo album, OREA. The eponymous title song quickly raced to #1, topping the charts for many weeks. In December, he released his second album, By Your Side. With his successful debut and entry into the entertainment industry, the Taiwanese media dubbed him as Taiwan's "Little Sun".

In July 1996, he made his film debut in Hi Sir. Chung also contributed to the Soundtrack of the film, singing the theme song "Ai Bu Shi Shou". Hi Sir topped box office charts and became the biggest summer hit of 1996. In October, he released his first Cantonese album titled Present, officially embarking onto the Hong Kong music industry.

In October 1998, Chung released his sixth album, Hello, How Are You. The title song "Subway" was nominated at the Golden Melody Awards for Best Composition. Chung also received praise for penning the lyrics to most of his songs, including "Really Like Me", "Us" and "I Really Want to Know".

From 1999 onwards, Chung moved to the Mainland to focus on his acting career. The same year, he played his first television leading role in wuxia drama Windstorm. In 2001, Chung had a guest role in the pan-asia hit drama Meteor Garden.

Chung resumed his singing career in 2004. He published his seventh Mandarin-language album, Soul Man. The album received positive reviews from music critics.

Chung first gained recognition for his portrayal of two Qing-dynasty figures. In 2006, Chung starred in Secret History of Kangxi, portraying a famous Chinese poet Nalan Xingde. In 2008, Chung starred in Royal Tramp, portraying Kangxi Emperor.

In 2009, Chung starred in King of Shanghai. He was nominated for the Most Popular Actor award at the Magnolia Awards.

In January 2010, Chung released his eleventh Mandarin album, All Eyes On Me. Upon its release in mainland China in October, the album topped the charts and Chung won the Best Male Stage Performance at the Beijing Pop Music Awards. Chung once again won the award in 2011, with his single "One Day We Will Grow Old". The song was also named as one of the Top 10 songs of the year. In October 2011, he held his first solo concert titled "Wallace S-Party Concert" at Shanghai's Luwan Gymnasium.

Chung was once again nominated for the award the subsequent year with his performance in the wuxia drama The Magic Blade (2012), adapted from Gu Long's novel of the same title. Chung was also awarded the Best Actor award at the 3rd LeTV awards for his performance.

In 2013, Chung starred in the romance drama Best Time, based on Tong Hua's novel The Most Beautiful Time. The series was a ratings hit, leading to increased popularity for Chung. Chung was awarded the Best Actor award for the Hong Kong and Taiwan region at the 4th LeTV awards. The same year, he starred in the wuxia drama The Demi-Gods and Semi-Devils, adapted from Louis Cha's novel Demi-Gods and Semi-Devils. He then starred in crime thriller film Drug War, directed by Johnnie To.

In 2014, Chung played dual roles in the drama The Stand-In, adapted from the film Bodyguards and Assassins. The series was nominated for the Outstanding Television Series award at the Flying Apsaras Awards. He also starred alongside Feng Shaofeng and Chen Bolin in the road trip comedy film The Continent, directed by Han Han.

In 2015, Chung starred in the romance melodrama in My Sunshine, based on the novel Silent Separation written by Gu Man. The series was a major hit, and propelled Chung to mainstream popularity in China. Chung received the Asia Star Grand Award at the 2015 Seoul International Drama Awards. The same year, he announced his directorial debut, Sandglass, a youth movie adapted from best-selling author Rao Xueman's book by the same name.

In 2016, Chung starred in the action comedy film Bounty Hunters, directed by Shin Terra, alongside Tiffany Tang and Korean actor Lee Min-ho. The same year, he starred in the crime thriller Tik Tok. Chung then played the antagonist in crime drama film Three, which also stars Zhao Wei and Louis Koo. He won the Most Anticipated Actor award at the 19th China Movie Channel Media Award.

In 2017, Chung starred in the historical romance drama General and I, adapted from the novel A Lonesome Fragrance Waiting to be Appreciated, alongside AngelaBaby. The same year, he was cast in the modern romance drama Memories of Love alongside Jiang Shuying.