In charge of the organisation of games were the agonothetai, 'those who held the games'. This title had several variations, such as the archaic synonym athlothetes. At the Olympic and Nemean games, the president-organisers were called 'hellanodikai'.

The presidency of the games was a very honourable function, usually held by rich aristocrats. They acted at the same time as sponsors, paying part of the costs of the organisation and the prizes out of their own pocket. They could take the initiative to hold the office themselves, but as for any other office, they could also be appointed for it. At small, local games, which needed relatively little money and organisation, there was usually only one agonothetes, but for larger games, a board could be appointed. There are known a few female agonothetai from the Roman period. If someone had given a large donation, for example an estate that produced enough to pay for the games eternally, he was called 'eternal agonothetes'.

The organisers had several tasks: guarding over the smooth proceedings of the games, placing the athletes in age categories, nominating the victor in situations of doubt and awarding the prizes. For the more practical tasks they had subordinates: umpires, for example, to keep the athletes in check in the heat of the match, policemen to keep order among the crowd of spectators, etc. The agonothetai themselves were in the first place presidents, who watched the games from an seat of honour and were praised for their generosity. Their name could also be used to date the games.