Swedish grammar is either the study of the grammar of the Swedish language, or the grammatical system itself of the Swedish language. Swedish is descended from Old Norse. Compared to its progenitor, Swedish grammar is much less characterized by inflection. Modern Swedish has two genders and no longer conjugates verbs based on person or number. Its nouns have lost the morphological distinction between nominative and accusative cases that denoted grammatical subject and object in Old Norse in favor of marking by word order. Swedish uses some inflection with nouns, adjectives, and verbs. It is generally a subject–verb–object (SVO) language with V2 word order.

Nouns have one of two grammatical genders: common (utrum) and neuter (neutrum), which determine their definite forms as well as the form of any adjectives and articles used to describe them. Noun gender is largely arbitrary and must be memorized; however, around three quarters of all Swedish nouns are common gender. Living beings are often common nouns, like in en katt "a cat", en häst "a horse", en fluga "a fly", etc (see also Gender in Danish and Swedish).

Swedish once had three genders—masculine, feminine and neuter. Though the three-gender system is preserved in a number of dialects and traces of it still exist in certain expressions, masculine and feminine nouns have today merged into the common gender in the standard language. A remnant of the masculine gender can still be expressed in the singular definite form of adjectives according to natural gender (male humans), in the same way as personal pronouns, han and hon, are chosen for representing nouns in contemporary Swedish (male/female human beings and optionally animals).

There is a small number of Swedish nouns that can be either common or neuter gender. The database for Svenska Akademiens ordlista 12 contained 324 such nouns.

There are traces of the former four-case system for nouns evidenced in that pronouns still have subject, object (based on the old accusative and dative form) and genitive forms. Nouns make no distinction between subject and object forms, and the genitive is formed by adding -s to the end of a word. This -s genitive functions more like a clitic than a proper case and is nearly identical to the possessive suffix used in English. Note, however, that in Swedish orthography this genitive -s is appended directly to the word and is not preceded by an apostrophe. This does not cause confusion as it would in English because Swedish does not use an "-s" suffix for plurals.

Swedish nouns are inflected for number and definiteness and can take a genitive suffix. They exhibit the following morpheme order:

Nouns form the plural in a variety of ways. It is customary to classify Swedish nouns into five declensions based on their plural indefinite endings: -or, -ar, -(e)r, -n, and no ending.

The definite article in Swedish is mostly expressed by a suffix on the head noun, while the indefinite article is a separate word preceding the noun. This structure of the articles is shared by the Scandinavian languages. Articles differ in form depending on the gender and number of the noun.