Edh (or eth or ) is a letter (capital Ð, lower-case ð) used in Old English (Anglo-Saxon) and present-day Icelandic and Faroese. The letter had its origin as a d with a cross-stroke added. The lowercase version has retained the flowing shape of a Medieval scribe's d, which d itself has not.

In Icelandic, ð represents a voiced dental fricative, as in th in English "them". In the Icelandic and Faroese alphabets, ð follows d. In Anglo-Saxon, ð may represent the same sound as in Icelandic, or the voiceless th of "thread", both of which were also represented by thorn (þ). Eth was usually used when the diagraph was voiced (as in "the" or "that"). In Middle English, ð was no longer used.

Lower-case edh is used as a symbol in the International Phonetic Alphabet, again for a voiced dental fricative.

See also: Þ, Yogh, Œ