A pyridinecarboxylic acid is any member of a group of organic compounds which are monocarboxylic derivatives of pyridine. Pyridinecarboxylic acid comes in three isomers:
| Common Name | Picolinic acid | Nicotinic acid/Niacin | Isonicotinic acid | |
| Systematic Name | 2-pyridinecarboxylic acid | 3-pyridinecarboxylic acid | 4-pyridinecarboxylic acid | |
| Structural Formula | ||||
| CAS Registry Number | 98-98-6 | 59-67-6 | 55-22-1 |