Dominant firms that are accused of abusive behaviour may try to invoke an objective justification. If an objective justification is successfully invoked, the Article 102 of the Treaty on the Functioning of the European Union (TFEU) prohibition does not apply. The objective justification plea is useful to provide more legal certainty and coherence as to the application of Article 102 TFEU and appears to fit well within the 'effects-based' approach advocated by many. In this article, I discuss three types of objective justification. The first source is legitimate business behaviour, which basically encompasses all actions that can be qualified as 'competition on the merits'. A second source is public interest considerations, where a higher (non-competition) goal trumps the application of Article 102 TFEU. A third source is efficiency. If the conduct leads to a net gain in consumer welfare, it may be objectively justified. The application of objective justification may depend on many factors. The proportionality criterion, the necessity test, the dominant firm's intent and the effect of the conduct may all have a role to play. In this paper, I argue that the applicability of these conditions depend on the type of justification being invoked.