| Sport | Swimming |
|---|---|
| Competition Category | World Championships |
| Years | 2006—2025 |
| Editions | 10 |
| Competitors | 1767 |
| Countries | 82 |
The 2021 edition originally scheduled for Kazan (RUS) from 24 to 29 August 2021 was first postponed due to the COVID-19 pandemic and later also moved to Lima (PER) due to the invasion of the Russian Federation in Ukraine.
| Edition | Host City | Country | Held | Events | Competitors | Countries |
|---|---|---|---|---|---|---|
| 2006 World Junior Swimming Championships | Rio de Janeiro | 22 – 27 August 2006 | 40 | 223 | 34 | |
| 2008 World Junior Swimming Championships | Monterrey | 8 – 13 July 2008 | 40 | 120 | 18 | |
| 2011 World Junior Swimming Championships | Lima | 16 – 21 August 2011 | 40 | 116 | 19 | |
| 2013 World Junior Swimming Championships | Dubai | 26 – 31 August 2013 | 42 | 413 | 49 | |
| 2015 World Junior Swimming Championships | Singapore | 25 – 30 August 2015 | 42 | 415 | 47 | |
| 2017 World Junior Swimming Championships | Indianapolis | 23 – 28 August 2017 | 42 | 109 | 18 | |
| 2019 World Junior Swimming Championships | Budapest | 20 – 25 August 2019 | 42 | 116 | 20 | |
| 2022 World Junior Swimming Championships | Lima | 30 August – 4 September 2022 | 42 | 110 | 22 | |
| 2023 World Junior Swimming Championships | Netanya | 4 – 9 September 2023 | 42 | 116 | 21 | |
| 2025 World Junior Swimming Championships | Oradea | 18 – 24 August 2025 | 42 | 114 | 25 |
| Pos | Country | 🥇 Gold | 🥈 Silver | 🥉 Bronze | Total | |
|---|---|---|---|---|---|---|
| 1 | United States | 94 | 74 | 65 | 233 | |
| 2 | Australia | 41 | 31 | 26 | 98 | |
| 3 | Russia | 36 | 39 | 43 | 118 | |
| 4 | Japan | 33 | 42 | 38 | 113 | |
| 5 | Italy | 27 | 38 | 48 | 113 | |
| 6 | Canada | 18 | 26 | 33 | 77 | |
| 7 | Hungary | 13 | 21 | 3 | 37 | |
| 8 | Great Britain | 13 | 19 | 24 | 56 | |
| 9 | Turkey | 13 | 2 | 3 | 18 | |
| 10 | Spain | 12 | 7 | 12 | 31 | |
| 11 | Poland | 12 | 6 | 13 | 31 | |
| 12 | China | 11 | 14 | 13 | 38 | |
| 13 | Ukraine | 11 | 4 | 5 | 20 | |
| 14 | New Zealand | 10 | 2 | 1 | 13 | |
| 15 | Lithuania | 7 | 4 | 4 | 15 | |
| 16 | Romania | 6 | 5 | 4 | 15 | |
| 17 | Germany | 5 | 12 | 5 | 22 | |
| 18 | France | 5 | 6 | 9 | 20 | |
| 19 | Neutral Participant | 5 | 5 | 5 | 15 | |
| 20 | Brazil | 3 | 11 | 6 | 20 | |
| 21 | South Africa | 3 | 6 | 9 | 18 | |
| 22 | Greece | 3 | 3 | 6 | 12 | |
| 23 | Croatia | 3 | 2 | 3 | 8 | |
| 24 | Argentina | 3 | 2 | 2 | 7 | |
| 25 | Ireland | 3 | 1 | 2 | 6 | |
| 26 | Portugal | 3 | 0 | 0 | 3 | |
| 27 | Czech Republic | 2 | 5 | 5 | 12 | |
| 28 | Austria | 2 | 3 | 4 | 9 | |
| 29 | Denmark | 2 | 1 | 3 | 6 | |
| 30 | Belgium | 2 | 1 | 0 | 3 | |
| = | Bosnia and Herzegovina | 2 | 1 | 0 | 3 | |
| 32 | Hong Kong | 2 | 0 | 2 | 4 | |
| 33 | Slovenia | 2 | 0 | 0 | 2 | |
| 34 | Serbia | 1 | 4 | 3 | 8 | |
| 35 | Belarus | 1 | 3 | 1 | 5 | |
| 36 | Bulgaria | 1 | 2 | 2 | 5 | |
| = | South Korea | 1 | 2 | 2 | 5 | |
| 38 | Estonia | 1 | 1 | 1 | 3 | |
| 39 | Serbia and Montenegro | 1 | 1 | 0 | 2 | |
| = | Trinidad and Tobago | 1 | 1 | 0 | 2 | |
| 41 | Egypt | 1 | 0 | 1 | 2 | |
| 42 | Indonesia | 1 | 0 | 0 | 1 | |
| 43 | Sweden | 0 | 4 | 2 | 6 | |
| 44 | Malaysia | 0 | 2 | 0 | 2 | |
| 45 | Cyprus | 0 | 1 | 1 | 2 | |
| 46 | Nigeria | 0 | 1 | 0 | 1 | |
| 47 | Venezuela | 0 | 0 | 3 | 3 | |
| 48 | Ecuador | 0 | 0 | 1 | 1 | |
| = | Panama | 0 | 0 | 1 | 1 | |
| = | Slovakia | 0 | 0 | 1 | 1 | |