This is a sub-list from List of doping cases in sport representing a full list of surnames starting with J.
| Name | Country | Event | Banned substance(s) | Reference(s) |
|---|---|---|---|---|
| Mette Jacobsen |
 Denmark
|
Swimming | Prednisolone, Prednisone | |
| Mahmoud Jadaan |
 Syria
|
Swimming | Metenolone | |
| Jörg Jaksche |
 Germany
|
Cycling | Erythropoietin (EPO) | |
| Laurent Jalabert |
 France
|
Cycling | Erythropoietin (EPO) | |
| Jiraporn Janchum |
 Thailand
|
Weightlifting | Methandienone | |
| Paulo Bruno Janeiro |
 Brazil
|
Swimming | Cannabis | |
| Michal Jarczak |
 Poland
|
Gymnastics | THC | |
| Daniel Jardemyr |
 Sweden
|
Ice hockey | Amphetamine | |
| Sabri Jari |
 Tunisia
|
Swimming | Refusal to submit to doping test | |
| Mohammed Jassim |
 Iraq
|
Weightlifting | Cortisone | |
| Ernst Jean-Joseph |
 Haiti
|
Football (soccer) | Phenmetrazine | |
| Leon Jeanne |
 Wales
|
Football (soccer) | ||
| Genevieve Jeanson |
 Canada
|
Cycling | Erythropoietin (EPO) | |
| Brian Dalgaard Jensen |
Denmark
|
Cycling | Erythropoietin (EPO) | |
| Knud Enemark Jensen |
Denmark
|
Cycling | Amphetamines | |
| Aubrey Jesseau |
Canada
|
Canadian football | Stanozolol | |
| Tomas Johansson |
Sweden
|
Sport wrestling | Anabolic steroids | |
| Therese Johaug |
 Norway
|
Cross-country skiing | Anabolic steroid Clostebol | |
| Ben Johnson |
Canada
|
Sprinting | Stanozolol | |
| Gea Johnson |
 United States
|
Athletics (Hept) | Anabolic steroids | |
| Gea Johnson |
United States
|
Weightlifting | Epitestosterone | |
| Gea Johnson |
United States
|
Cycling | Modafinil | |
| Willie Johnston |
 Scotland
|
Football (soccer) | Reactivan | |
| Harrison Jones |
United States
|
Diving | Cannabis | |
| Roy Jones Jr. |
United States
|
Boxing | Androstenedione (Banned substance by the IBF but available legally over-the-counter in the US at time of use) | |
| Ahmad Joughili |
Syria
|
Weightlifting | Metandienone | |
| Alberto Jose |
 Dominican Republic
|
Weightlifting | Methandienone, Dehydrochlormethyltestosterone | |
| Mi Naw Ju |
 Myanmar
|
Weightlifting | ||
| Rui Jorge |
 Portugal
|
Association football | Budesonide (ban lifted due to Sporting CP's failure to notify authorities of his medical exemption) | |
| Miguel Juarez |
 Venezuela
|
Swimming | Nandrolone | |
| Olivera Juric |
 Bosnia and Herzegovina
|
Weightlifting | Metandienone | |
| Ladislav Jusko |
 Czech Republic
|
Water polo | Cannabis |