Spanish verbs form one of the more complex areas of Spanish grammar. Spanish is a relatively synthetic language with a moderate to high degree of inflection, which shows up mostly in Spanish conjugation.

As is typical of verbs in virtually all languages, Spanish verbs express an action or a state of being of a given subject, and like verbs in most Indo-European languages, Spanish verbs undergo inflection according to the following categories:

The modern Spanish verb paradigm (conjugation) has 16 distinct complete forms (tenses), i.e. sets of forms for each combination of tense, mood and aspect, plus one incomplete tense (the imperative), as well as three non-temporal forms (the infinitive, gerund, and past participle). Two of the tenses, namely both subjunctive futures, are now obsolete for most practical purposes.

The 16 "regular" forms (tenses) include 8 simple tenses and 8 compound tenses. The compound tenses are formed with the auxiliary verb haber plus the past participle. Verbs can be used in other forms, such as the present progressive, but in grammar treatises they are not usually considered a part of the paradigm but rather periphrastic verbal constructions.

Spanish verbs are inflected to convey mood, tense, voice, and aspect, and to agree with person and number.

Spanish verbs are conjugated in three persons, each having a singular and a plural form. In some varieties of Spanish, such as that of the Río de la Plata Region, a special form of the second person is used.

Spanish is a pro-drop language, meaning that subject pronouns are often omitted.

The grammatical first person refers to the speaker ("I"). The first person plural refers to the speaker together with at least one other person.