He is best known for his leading roles in the television series Something Happened in Bali (2004), Spring Day (2005), That Winter, the Wind Blows (2013), It's Okay, That's Love (2014), and Moving (2023).

In film, he is known for his roles in The Classic (2003), A Dirty Carnival (2006), A Frozen Flower (2008), The King (2017), The Great Battle (2018), and Escape from Mogadishu (2021).

[9] Zo first drew notice with a supporting role in the 2001 television drama Piano, co-starring Go Soo and Kim Ha-neul.

[12] He also starred in several music videos of popular boy band g.o.d, a fellow SidusHQ artiste at that time, and was directed by actor Jung Woo-sung.

[13] In 2003, Zo starred in three romantic films, most notably Kwak Jae-yong's The Classic, with Son Ye-jin and Cho Seung-woo.

[17][18] Zo collaborated with renowned director Yoo Ha in his next two films: 2006's A Dirty Carnival, in which he played a charismatic small-time gangster who seeks a happier life,[19][20] and 2008's A Frozen Flower, a Goryeo-period film where his royal bodyguard character is caught in a love triangle between the king and the queen.

[21][22] On April 7, 2009, Zo enlisted for his two-year mandatory military service; he reportedly wanted to join the Air Force to follow in the footsteps of his father, who served as a non-commissioned officer.

[28] In 2013, he co-starred in the melodrama That Winter, the Wind Blows alongside Song Hye-kyo,[29][30] a remake of the Japanese drama Forget Love (愛なんていらねえよ、夏, Ai nante Irane yo, Natsu).

[32][33] A year later, Zo reunited with That Winter's teleplay writer and director in SBS's medical melodrama It's Okay, That's Love opposite Gong Hyo-jin.

[37] In 2017, Zo starred in the crime thriller The King alongside Jung Woo-sung, directed by The Face Reader director Han Jae-rim.

[63] According to a non-governmental organization MIRAL Welfare Foundation, Jo has generously donated 500 million won (almost 440 thousand dollars) to help the people in Tanzania.