In the labor relations context, a process for a union and employer to resolve disagreements concerning interpretations or applications of an existing collective bargaining agreement (CBA). Typically, parties agree on a process for raising and resolving these disputes that culminates in the parties submitting the CBA interpretation or application issues to an arbitrator. The parties appear at a hearing and present arguments and evidence to the arbitrator supporting their positions on disputed terms in the CBA. The arbitrator's decision in a grievance arbitration is final and binding on both parties. The decision may also be considered precedential in future arbitrations to interpret or apply that CBA.

Grievance arbitration is a common mechanism for resolving CBA disputes in all sectors and industries. Parties often use it as an alternative to work stoppages such as strikes or lockouts.

The Railway Labor Act (RLA) prohibits covered employees from striking over CBA interpretation and application disputes, which it calls minor disputes. Accordingly, the RLA requires that minor disputes be resolved through grievance arbitration before one of the following authorized arbitration tribunals:

For more information, see Practice Notes, Railway Labor Act: Overview and Labor Law: Overview.