This page lists the countries and benchmarking participants (regional entities) that are taking part in TIMSS 2023 at one or both grade levels.
Countries Participating in TIMSS 2023
| Albania | Iraq | Poland |
| Armenia | Ireland | Portugal |
| Australia | Israel | Qatar |
| Austria | Italy | Romania |
| Azerbaijan | Ivory Coast | Russian Federation |
| Bahrain | Japan | Saudi Arabia |
| Belgium (Fl.) | Jordan | Serbia |
| Belgium (Fr.) | Kazakhstan | Singapore |
| Bosnia and Herzegovina | Korea | Slovak Republic |
| Brazil | Kosovo | Slovenia |
| Bulgaria | Kuwait | South Africa |
| Canada | Latvia | Spain |
| Chile | Lithuania | Sweden |
| Chinese Taipei | Macao SAR | Turkey |
| Cyprus | Malaysia | United Arab Emirates |
| Czech Republic | Malta | United States |
| Denmark | Montenegro | Uzbekistan |
| Egypt | Morocco | Benchmarking Participants |
| England | Netherlands | Ontario, Canada |
| Finland | New Zealand | Quebec, Canada |
| France | North Macedonia | Moscow City, Russia |
| Georgia | Northern Ireland | Abu Dhabi, UAE |
| Germany | Norway | Dubai, UAE |
| Hong Kong SAR | Oman | Total: 67 countries |
| Hungary | Palestine | +5 Benchmarking |