All available race results Willem "Guillaume" Muller
| Date | Race | Rank |
| 09/06 | Spa 10 km handicap | 4 |
| 25/08 | Huy - Grande Internationale | 4 |
Rider information for 1889
| Rank | 163 |
| Score | 50 |
| Name | Willem "Guillaume" MULLER |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| 10/08 | Championnat de Belgique - 10 km | 3 |
Rider information for 1890
| Rank | 417 |
| Score | 23 |
| Name | Willem "Guillaume" MULLER |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| 04/10 | Bruxelles-Parc du Cinquantenaire | 2 |
| 25/10 | Course Coulisse Théatrale & Sportive | 45 |
Rider information for 1891
| Rank | 601 |
| Score | 27 |
| Name | Willem "Guillaume" MULLER |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| 03/04 | Course bénéficiaire aux victimes de la catastrophe d'Anderlues | 3 |
| 29/05 | Liège - Bastogne - Liège | 10 |
| 17/07 | Wavre - Nivelles | 5 |
Rider information for 1892
| Rank | 32 |
| Score | 206 |
| Name | Willem "Guillaume" MULLER |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| 13/05 | Wavre - Hannut - Wavre | 4 |
| 14/05 | Liège - Course de 1 heure | 5 |
| 30/07 | Dinant - Namur - Givet - Dinant | 5 |
| 20/08 | Huy - Namur - Huy - Amay - Huy | 16 |
Rider information for 1893
| Rank | 173 |
| Score | 62 |
| Name | Willem "Guillaume" MULLER |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| 13/05 | Amsterdam - Amersfoort - Amsterdam | 8 |
Rider information for 1895
| Rank | 337 |
| Score | 16 |
| Name | Willem "Guillaume" MULLER |
| Country | Belgium |
| Team | Individual |
No results available in season 1897.
Rider information for 1897
| Rank | 255 |
| Score | 23 |
| Name | Willem "Guillaume" MULLER |
| Country | Belgium |
| Team | Individual |