Christian Harrison (born May 29, 1994) is an American professional tennis player who specializes in doubles. He has a career-high ATP doubles ranking of world No. 15 achieved on 3 November 2025 and a singles ranking of No. 198 achieved on 2 July 2018. His best achievements are reaching the semifinals of the 2025 French Open with Evan King, and the mixed doubles semifinals of the 2018 US Open, partnering Christina McHale. He has won three ATP Tour doubles titles with King.

Christian was coached by his father, Pat Harrison, and attended the IMG Academy in Bradenton, Florida. He is the younger brother of Ryan Harrison.

In July, Christian made it to the quarterfinals of the Lexington, Kentucky Challenger event. Christian was awarded a wildcard into the 2012 US Open to play doubles alongside Ryan Harrison, where they reached the quarterfinals.

Earlier in the year he reached the quarterfinals, semifinals, the final, and won, respectively, the four Futures events in which he participated. He failed to qualify in Indian Wells, losing in the first round of qualifying to Ernests Gulbis, who made a deep run to the fourth round after qualifying. However, he did take a set off Gulbis.

Harrison won his first ATP World Tour match against Alejandro Falla at the BB&T Atlanta Open. He then lost in the next round to John Isner in three tight sets.

Harrison spent 2014 and 2015 recovering from several surgeries.

Harrison reached the final round of qualifying at the 2016 US Open after beating Luke Saville and second seed Konstantin Kravchuk in two three-set matches. He made it into main draw after beating Steven Diez also in three-set match. He was one set down at all three matches in qualifying. He lost in the first round to Paul-Henri Mathieu in straight sets.

He made his Masters 1000 singles debut at the 2017 Miami Open as a qualifier but lost to Dudi Sela in the first round. He received a wildcard to the 2017 US Open where he won his first round match in doubles with partner Christopher Eubanks.