Abstract Comparison expresses a relation involving two or more entities which are ordered on a scale with respect to a gradable property, called the parameter of comparison. In European languages, it is typically expressed through two constructions, comparatives and superlatives. Comparative constructions generally involve two entities, and indicate whether the compared entity shows a higher, lesser, or equal degree of the parameter with respect to the other entity, which is the standard of comparison. Superlatives set out one entity against a class of entities and indicate that the compared entity shows the highest or lowest degree of the parameter. Hence, comparatives may express either inequality (superiority or inferiority) or equality, whereas superlatives necessarily express superiority or inferiority. In traditional grammar, the terms comparative and superlative are primarily used to refer to the morphology of adjectives and adverbs in languages with synthetic marking (cf. Eng. slow, slower, slowest). However, while Latin has such synthetic marking, modern Romance languages no longer possess productive comparative or superlative suffixes. All Romance languages use analytic markers consisting of dedicated adverbs (e.g., Fr. plus ‘more’, moins ‘less’, aussi ‘as, also’) and determiners (e.g., Sp./It. tanto, Ro. atât ‘so much’). Superlatives are marked with the same markers and are mainly distinguished from comparatives by their association with definiteness. Another difference between comparatives and superlatives lies in the complements they license. Comparatives license a comparative complement, which may be clausal or phrasal, and which identifies the standard of comparison. As for superlatives, they license partitive PPs denoting the comparison set, which may be further specified by other PPs, a relative clause, or an infinitive clause. The Romance languages show many similarities with respect to the morphosyntactic encoding of comparatives and superlatives, but they also display important cross-linguistic differences. These differences may be related to the status of the comparative marker, the encoding of the standard marker, ellipsis phenomena in the comparative clause, and the dependence of the superlative on the definite article.