The Philippines is ranked as the 5th largest Christian-majority country on Earth in 2010^[update], with about 93% of the population being adherents. As of 2019^[update], it was the third largest Catholic country in the world and was one of two predominantly Catholic nations in Asia.

According to the National Statistics Office's national census for the year 2010, an estimated 90.1% of Filipinos were Christians; this consisted of 80.6% Catholic, 4% Iglesia ni Cristo, 1.0% Aglipayan, 2.7% Evangelical groups, and 3.4% other Christian groups including other Protestant denominations (Baptist, Pentecostal, Anglican, Methodist, and Seventh-day Adventist) as well as Orthodox. Around 5.6% of the whole country was Muslim; about 1-2% were Buddhist; 1.8% of the entire population adhered to other independent religions, while less than 0.1% (as of 2015) were irreligious. With this, the Philippines has consistently demonstrated a low level of government restrictions on religion, ensuring that citizens are free to practice their faiths openly, with minimal interference from state authorities, which reflects the country’s strong constitutional guarantee of religious freedom and diversity. According to the 2020 census, at least 84% of the population is Christian; about 79% belong to the Catholic Church while about 5% belong to Protestantism and other denominations such as Philippine Independent Church, Iglesia ni Cristo, Jehovah's Witnesses, Seventh-day Adventist Church, Apostolic Catholic Church, United Church of Christ in the Philippines, Members Church of God International (MCGI) and Pentecostals.

Many Filipinos in 2021 celebrated 500 years of Christian presence in the Philippines with Pope Francis commemorating March 16, the day Magellan introduced Catholicism with a mass on Limasawa, Leyte.

Early Christian presence in the Malay archipelago and the Philippine Islands may be traced to Arab Christian traders from the Arabian Peninsula. They had trade contacts with early Malayan Rajahs and Datus that had ruled these various Islands. Early Arabians had heard the gospel from Peter the Apostle at Jerusalem (Acts 2:11), as well as evangelized by Paul's ministry in Arabia (Galatians 1:17) and also by the evangelistic ministry of St Thomas. Later, these Arab traders along with Persian Nestorians, stopped by the Philippines on their way to Southern China for trade purposes. However, no solid efforts were made to evangelize the native population. With the spread of Islam in Arabia, much of the Christian heritage of Arabia had ended and the Arab travelers focused more on spreading Islam to Mindanao, through which they transmitted the knowledge of Jesus as a prophet to the Moro people.

In 1521, the Portuguese navigator and explorer Ferdinand Magellan under the service of Spain came across the Philippines while searching for the Spice Islands. Ferdinand Magellan and his men landed in Cebu Island in central Philippines.

At this time period, almost nothing was known to the West of the Philippines and so information on most pre-Hispanic societies in the islands date to the early period of Spanish contact. Most Philippine communities, with the exception of the Muslim sultanates in Mindanao and the Sulu Archipelago, were fairly small and lacking in complex centralised authority. This absence of centralised power meant that a minority of Spanish explorers were able to convert larger numbers of indigenous peoples than attempting such in larger, more organized, dominions such as the Indianised or Theravada Buddhist kingdoms in mainland Southeast Asia, the Malay Peninsula and the Indonesian Archipelago.

With his arrival in Cebu on March 17, 1521, his first attempt was to colonize the islands and to Christianise its inhabitants. The story goes that Magellan met with Rajah Humabon, ruler of the island of Cebu, who had an ill grandson. Magellan (or one of his men) was able to cure or help the young boy, and in gratitude Humabon allowed himself, his chief consort Humamay, and 800 of his subjects to be baptised en masse. In order to achieve this, Spain had three principal objectives in its policy towards the Philippines: the first was to secure Spanish control and acquisition of a share in the spice trade; use the islands in developing contact with Japan and China in order to further Christian missionaries’ efforts there; and lastly to spread their religion.

After Magellan was killed by natives, the Spanish later sent Miguel López de Legazpi. He arrived in Cebu from New Spain (now Mexico), where Spain introduced Christianity and colonisation in the Philippines took place. He then established the first Permanent Spanish Settlement in Cebu in 1565. This settlement became the capital of the new Spanish colony, with Legazpi as its first governor. After Magellan, Miguel López de Legazpi conquered the Islamised Kingdom of Maynila in 1570. The Spanish missionaries were able to spread Christianity in Luzon and the Visayas, but the diverse array of ethno-linguistic groups in the highland areas of Luzon avoided Spanish annexation owing to their remote and difficult mountainous region. Sultanates in Mindanao retained the Islamic faith, which had been present in the southern Philippines since some time between the 10th and 12th century, had slowly spread north throughout the archipelago, particularly in coastal areas. This resistance to Western intrusion makes this story an important part of the nationalist history of the Philippines. Many historians have claimed that the Philippines peacefully accepted Spanish rule; the reality is that many insurgencies and rebellions continued on small scales in different places through the Hispanic colonial period.