The Icelandic alphabet consists of the following letters:

A Á B (C) D Ð E É F G H I Í J K L M N O Ó P (Q) R S T U Ú V (W) X Y Ý (Z) Þ Æ Ö

The modern Icelandic alphabet has developed from a standard established in the 19th century, by the Danish linguist Rasmus Rask primarily. It is ultimately based heavily on an orthographic standard created in the early 12th century by a mysterious document referred to as The First Grammatical Treatise , author unknown. The standard was intended for what its author perceived to be a common language of Scandinavia, alias Old Norse. It did not have much influence, however, at the time.

The most defining characteristics of the alphabet were established in the old treatise:

• Use of the acute accent (originally to signify vowel length).
• Use of þ, borrowed from the Old English alphabet letter thorn, a language which the astute grammarian described as "more or less the same" as Old Norse.

The later Rasmus Rask standard was basically a re-enactment of the old treatise, with some changes to fit concurrent Germanic conventions, such as the exclusive use of k rather than c. Various old features, like ð, had actually not seen much use in the later centuries, so Rask's standard constituted a major change in practice.

Later 20th century changes are most notably the adoption of é, which had previously been written as je (reflecting the modern pronunciation), and the abolition of z, which had long been a mere etymological detail.

Recently most people have begun pronouncing Y and I in the same way as well as Ý and Í. As there is no difference in the pronunciation of those letters, they might be a candidate for future deprecation in the alphabet.