US Optimist Dinghy Association
- All about the USODA, membership list, local results, events calendar, gear exchange, and who/what/where information.
- http://www.usoda.org/

International Optimist Class Association - UK
- Contains news, club information, classes, forums, training and weather reports.
- http://www.optimistsailing.org.uk/

Irish Optimist Association
- Introduction by the President of IODAI, news, events, information package, photographs, archives, items for sale, and message board are included.
- http://www.iodai.com/

Bermuda Optimist Dinghy Association
- Offers, racing results, news, upcoming events, photo gallery, and contact information.
- http://www.boda.bm

International Optimist Dinghy Association
- The home base for Optimist enthusiasts, with information about the class, regatta information, and links to other Opti sites.
- http://www.optiworld.org/