No. All Saints Day began in the Catholic Church and is still one of its major feast days, but it is also observed by Anglican, Lutheran, Methodist and other Christian traditions. It is celebrated on November 1st.
Definition of All Saints Day
All Saints Day is a Christian holiday that honors the saints of the church — men and women believed to have lived and died in the Christian faith. It falls on November 1st, the day after All Hallows’ Eve (Halloween).
History of All Saints Day
All Saints Day has its roots in the early church’s practice of honoring martyrs. Over time the Catholic Church set a single yearly feast for all the saints, and other Western Christian traditions kept the date after the Reformation, even as their reasons for observing it differed.
All Saints Day in the Catholic Church
All Saints Day is a major feast in the Catholic Church, and in many countries with a strong Catholic heritage it is also a public holiday. Catholic observance centers on honoring canonized saints and, on the following day (All Souls’ Day), praying for the faithful departed.
How the holiday is celebrated
Observances vary by church and country. Many congregations hold a special worship service that names and remembers members who have died in the past year, often with candles or bells. In some places the day includes visiting cemeteries and decorating graves.
Is All Saints Day Celebrated Outside Christianity?
No. All Saints Day is a Christian observance kept by Catholic, Anglican, Lutheran, Methodist, and some other Protestant churches. Orthodox churches keep a related feast, All Saints Sunday, on a different date. It is not a holiday of another religion.
Summary
All Saints Day is not exclusively Catholic. It began as a Catholic feast day and remains central to Catholic practice, but Anglican, Lutheran, Methodist, and other Christian traditions also observe it on November 1st each year.