| Roles | Competed in Olympic Games | |
|---|---|---|
| Sex | Male | |
| Full name | Jónas O.•Halldórsson | |
| Used name | Jónas•Halldórsson | |
| Born | 13 June 1914 in Hnausi, Ölfus, Suðurland |  ISL |
| Died | 10 September 2005 (aged 91 years 2 months 27 days) in Seljahlíð, Sölvadalur, Norðurland eystra | ISL |
| NOC | Iceland | ISL |
| Games | Discipline (Sport) / Event | NOC / Team | Pos | Medal | As | |
|---|---|---|---|---|---|---|
| 1936 Summer Olympics | Water Polo (Aquatics) | ISL |
Jónas Halldórsson | |||
| Water Polo, Men (Olympic) | Iceland | =13 |
