Iliev holds the record for the highest number of appearances in the Bulgarian top league, with 461 – 318 for Cherno More, 86 for Lokomotiv and 57 for CSKA.

On 31 July 2004, Iliev helped Lokomotiv to win the Bulgarian Supercup and he made his debut for the Bulgaria national side under coach Hristo Stoichkov in the same year.

On 2 October 2008, Georgi scored the 2nd goal for the Sailors in the UEFA Cup match against VfB Stuttgart in the away 2–2 draw at the Mercedes-Benz Arena.

[7] Iliev signed with Chinese side Shijiazhuang Yongchang on 6 January 2014 on a two-year deal for a reported fee of €100,000.

Iliev, along with five other senior players, was omitted from the team squad for Cherno More's away game against eventual champions Ludogorets on the last day of the 2018-19 season.

[12][13] After the match, which Ludogorets won 4–1 to become Bulgarian champions for the eight consecutive year, Cherno More's manager Ilian Iliev confirmed that the players have been released[14] after failing a polygraph test[15][16] concerning their conduct in the 1–3 defeat against title-hopefuls CSKA Sofia on 4 May in Varna.

"[17] Georgi Iliev strongly contested the accusations stemming from the results, calling them "a filthy lie", and insisting on his and his colleagues' innocence.

[25] An occasional member of the Under 21 team, Iliev marked his international début under Hristo Stoichkov on 29 November 2004 in a friendly game against Egypt.