on 11 august 2014, tonev moved to scottish champions celtic on a season-long loan deal, with an option to buy. he made his debut on 13 september, starting in a 2–1 home win over aberdeen. aberdeen full-back shay logan accused tonev of having racially abused him during this match; tonev denies the allegations. on 30 october 2014, tonev was given a seven-match ban for "using abusive language of a racist nature". celtic confirmed that they would appeal the decision, as they believe him to be innocent. tonev then lost his appeal and celtic decided not to take the matter any further.