The most complete list is put together every year by Ticino per bambini. Click here for their link.
Vivi Lugano is a programme offered by the city of Lugano in your neighboorhood community: Vivi Lugano.
The WWF summer camps are very popular. Click here for the list of their Ticino section. Click here.
The World Wide Fund for Nature is an international non-governmental organization founded in 1961, and is working on issues regarding the conservation, research and restoration of the environment.
Sport Kids Week Summer camp are held in Tenero: click here.
For summer courses at the American School in Switzerland (TASIS) click here.
Another option is Tandem - Spicchi di vacanza: click here