A verbal noun or gerundial noun is a verb form that functions as a noun. An example of a verbal noun in English is 'sacking' as in the sentence "The sacking of the city was an epochal event" (sacking is a noun formed from the verb sack).

Verbal nouns are morphologically related to non-finite verb forms, but they are not themselves non-finite verbs. Non-finite verb forms are forms such as gerunds, infinitives and participles in English.

Some grammarians use the term "verbal noun" to cover verbal noun, gerund, and nominal infinitive. Some may use the term "gerund" to cover both verbal noun and gerund. "Verbal noun" has often been treated as a synonym for "gerund". This article includes only gerundial nouns within the scope of "verbal nouns", excluding gerunds, nominal infinitives, and nouns formed from verbs through derivational processes.

Outside of English, the term "verbal noun" may be used for 1) the citation form of verbs such as the masdar in Arabic and the verbal noun (berfenw) in Welsh or 2) declinable verb forms in Mongolian that can serve as predicates, comparable to participles but with a larger area of syntactic use