Christian Theoharous (Greek: Κρίστιαν Θεοχάρους, pronounced [θe.oˈxa.ru̯s]; born 6 December 1999) is an Australian professional footballer who plays as a winger for NPL Victoria club Heidelberg United.

Theoharous was born in Melbourne, Victoria to a Cypriot father and Australian mother of Greek descent. His father, Andrew Theoharous, was born in Pegeia, Cyprus and was a former footballer in the National Soccer League for Marconi and later for Bentleigh Greens, whom he captained for a decade. Like his father, Theoharous joined Bentleigh Greens at the age of six before eventually moving to the Victoria National Training Centre (FFV NTC).

On 27 February 2017, Theoharous signed with Melbourne Victory FC as a scholarship player, after having been part of the Victory's youth team since 2014.

Theoharous made his Victory debut in 2017 as an 83rd minute substitute for Daniel Georgievski in a 1–0 loss to Brisbane Roar. Theoharous scored his debut first team goal for the Victory against the Central Coast Mariners on 18 March 2018.

Despite becoming a regular first-team player in the 2017–18 season, he missed Victory's victorious Grand Final finish to the season after getting injured in the semi-final.

Borussia Mönchengladbach announced that he had signed for the club on their official website on 18 May 2018.

Theoharous spent three seasons at the club, playing for their reserve team in the fourth tier of German football, before he was released by Borussia Mönchengladbach in June 2021.

On 1 November 2021, Theoharous joined Australian A-League Men club Western United on a two-year scholarship deal. Theoharous made 4 league appearances for Western United before the club and player agreed to a mutual termination of his contract on 17 January 2023, midway through the second season of his two year deal.