Spanish orthography is the writing system for the Spanish language. It is fairly phonemic, especially in comparison to more opaque orthographies like English and Irish, having a relatively consistent mapping of graphemes to phonemes.

The Spanish language is written using the Spanish alphabet, which is the Latin alphabet with one additional letter, eñe (⟨ñ⟩), for a total of 27 letters. Although the letters ⟨k⟩ and ⟨w⟩ are part of the alphabet, they appear only in loanwords such as karate, kilo and walkman. Each letter has a single official name according to the Real Academia Española's new 2010 Common Orthography, but in some regions alternative traditional names coexist as explained below.

^1 The sequence ⟨ch⟩ represents the affricate /tʃ/. The digraph was formerly treated as a single letter, called che.

^2 The phonemes /θ/ and /s/ have merged in many dialects; see ceceo.

^3 With the exception of hámster and albahaca, which have /x/.

^4 When ⟨l⟩ is written double (e.g. calle), it represents the palatal lateral /ʎ/ in a few dialects; but in most dialects—because of the historical merger called yeísmo—it, like the letter ⟨y⟩, represents the phoneme /ʝ/.