Eiður Smári Guðjohnsen (born 15 September 1978) is an Icelandic footballer who currently plays for AEK Athens F.C. in the Superleague Greece. He has previously played for Premier League club Chelsea and FC Barcelona of Spain, having made his name with Bolton Wanderers. He was the captain of the Iceland national team until manager Ólafur Jóhannesson took over the team. Throughout his professional career, Guðjohnsen has scored 160 goals in all competitions with his clubs and the national team. He is the son of Arnór Guðjohnsen, a former professional footballer. He is often considered to be one of the greatest Icelandic footballers, having won titles in the Netherlands, Spain, and England as well as the Champions League.

On 24 April 1996, Guðjohnsen and his father Arnór entered football history when playing in an international friendly for Iceland against Estonia in Tallinn. Arnór started the match, and Guðjohnsen came on in the second half as a substitute for his father.

Both father and son have later expressed bitterness at the fact that they were not allowed to play together in the match. The president of the Icelandic FA, Eggert Magnússon (later of West Ham United) gave the coach, Logi Ólafsson, an express order to not play them together because he wanted it to happen on home turf, when Iceland played Macedonia two months later in the first qualification round for the 1998 FIFA World Cup.