Demetrius Vikelas, also known as Bikelas (Δημήτριος Βικέλας; February 15, 1835 - July 20, 1908) was a Greek businessman and writer; he was the first president of the International Olympic Committee (IOC), from 1894 to 1896.

After a childhood spent in Greece and Constantinople, he found fortune in London, where he married. He then moved to Paris, on account of his wife. Abandoning business, he dedicated himself to literature and history, and published numerous novels, short stories and essays, which earned him a distinguished reputation. Because of his reputation and the fact that he lived in Paris, he was chosen to represent Greece in a congress called by Pierre de Coubertin in June 1894, which decided to re-establish the Olympic Games and to organise them in Athens in 1896, designating Vikelas to preside over the organisation committee. After the Games were over, he stepped down, remaining in Athens until his death in 1908.