There are two major religions in Eritrea, Christianity and Islam, however, the number of adherents is subject to debate. Eritrea: Religious Distribution (2002) indicates that Christianity makes up 64% of the population with Islam making up 37%. According to the Pew Research Center (2010), 62.9% are Christian, mostly followers of Oriental Orthodoxy, and to a lesser extent, Roman Catholicism, whilst the remaining 36.5% of the population are Muslim. In 2010 the United States Department of State (USDoS) estimated that 50% of the population was Muslim (Sunni) and around 48% Christian.Eritrea along with its southern neighbour Ethiopia was one of the first Christian countries in the world having officially adopted Christianity as the state religion in the 4th century. At the same time, it was also one of the first Muslim settlements in Africa, where a group of Muslims facing persecution in Mecca migrated to Abyssinia, (now Ethiopia) through modern day Eritrea.

The denominations of the religions in Eritrea also differ from source to source.

Eritrea ( /ˌɛrɨˈtreɪ.ə/ or /ˌɛrɨˈtriːə/;Ge'ez: ኤርትራ ʾErtrā, Arabic: إرتريا Iritrīyā), officially the State of Eritrea, is a country in the Horn of Africa. Eritrea is the Italian form of the Greek name Ἐρυθραίᾱ (Erythraíā), meaning "red [land]". The capital is Asmara. It is bordered by Sudan in the west, Ethiopia in the south, and Djibouti in the southeast. The northeast and east of the country has an extensive coastline on the Red Sea, directly across from Saudi Arabia and Yemen. The Dahlak Archipelago and several of the Hanish Islands are part of Eritrea. Eritrea's size is approximately 117,600 km² (45,406 sq mi) with an estimated population of 6 million.

Together with northern Somalia, Ethiopia, Djibouti, and the Red Sea coast of Sudan, Eritrea is considered the most likely location of the land known to the ancient Egyptians as Punt (or "Ta Netjeru", meaning "God's Land"), whose first mention dates to the 25th century BC. The ancient Puntites were a nation of people that had close relations with Pharaonic Egypt during the times of Pharaoh Sahure and Queen Hatshepsut.