| Continent: | Europe U-16 |
| Year: | 2003 |
| Host: | Spain |
| Dates: | 18–27 July 2003 |
| Teams: | 12 |
| Federations: | 1 |
| Cities: | 1 |
| Champions: | Serbia and Montenegro |
| Title Number: | 4 |
| Mvp: | Nemanja Aleksandrov |
| Ppg P: |  Luigi Da Tome (21.1) |
| Ppg T: | (89.6) |
| Rpg P: |  José Ángel Antelo (13.8) |
| Rpg T: | (42.0) |
| Apg P: |  Cenk Akyol (3.0) |
| Apg T: | (10.4) |
| Website: | Official website (archive) |
| Prevseason: | 2001 |
| Nextseason: | 2004 |
The 2003 FIBA Europe Under-16 Championship (known at that time as 2003 European Championship for Cadets) was the 17th edition of the FIBA Europe Under-16 Championship. The city of Madrid, in Spain, hosted the tournament. Serbia and Montenegro won the trophy for the fourth time in a row.
There were two qualifying rounds for this tournament. Twenty-four national teams entered the qualifying round. Fifteen teams advanced to the Challenge Round, where they joined Lithuania, Greece and France. The remaining eighteen teams were allocated in three groups of six teams each. The three top teams of each group joined Serbia and Montenegro (title holder), Russia (runner-up) and Spain (host) in the final tournament.
The twelve teams were allocated in two groups of six teams each.
| Team advanced to Quarterfinals | ||
| Team competed in 9th–12th playoffs |
| width=170 | Team | width=25 | Pld | width=25 | W | width=25 | L | width=35 | PF | width=35 | PA | width=25 | Pts |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 5 | 0 | 417 | 321 | 10 | ||||||||
| 5 | 4 | 1 | 398 | 366 | 9 | ||||||||
| 5 | 3 | 2 | 420 | 378 | 8 | ||||||||
| 5 | 2 | 3 | 369 | 345 | 7 | ||||||||
| 5 | 1 | 4 | 335 | 426 | 6 | ||||||||
| 5 | 0 | 5 | 315 | 418 | 5 |
| width=170 | Team | width=25 | Pld | width=25 | W | width=25 | L | width=35 | PF | width=35 | PA | width=25 | Pts |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 5 | 5 | 0 | 459 | 329 | 10 | ||||||||
| 5 | 3 | 2 | 349 | 365 | 8 | ||||||||
| 5 | 2 | 3 | 329 | 334 | 7 | ||||||||
| 5 | 2 | 3 | 315 | 363 | 7 | ||||||||
| 5 | 2 | 3 | 327 | 334 | 7 | ||||||||
| 5 | 1 | 4 | 321 | 375 | 6 |
| Rank | Team | |
|---|---|---|
| 4th | ||
| 5th | ||
| 6th | ||
| 7th | ||
| 8th | ||
| 9th | ||
| 10th | ||
| 11th | ||
| 12th |