Ragnarok Online is a free-to-play fantasy MMORPG developed by South Korean developer GRAVITY Co., Ltd. for Microsoft Windows. It is loosely based on the South Korean manhwa Ragnarok: Into the Abyss by Lee Myung-jin. It is the first game in the Ragnarok franchise and is best known in the Philippines as the first officially licensed published MMORPG in the country.

Except for the Japanese and Vietnamese services, almost all of the active official services are handled by publishers that are subsidiaries of or are related to the game's developer, GRAVITY.

A Web3 variation of Ragnarok Online called Ragnarok Landverse was launched in 2023, and another variation called Ragnarok Landverse: Genesis was launched in 2025. The Ragnarok franchise has also released multiple spin-offs on the mobile platform.

The following services are/were marketed to the Philippine region.

• International Ragnarok Online (iRO) is listed above, as accounts from Philippine Ragnarok Online were migrated to a new server named Thor in iRO in 2015.
• RO Extreme did not migrate player accounts in 2021.

• September 2003: Philippine Ragnarok Online (pRO) was launched commercially in the Philippines under Level Up!.
• March 31, 2015: pRO was shut down. Player accounts were migrated to International Ragnarok Online on a new server named Thor.
• June 20, 2017: A new Ragnarok Online service in the Philippines was published by Electronics Extreme Ltd. called RO Extreme. RO Extreme also published a separate MY/SG service.
• July 10, 2019: RO Extreme's Philippine service was merged with the Malaysian/Singaporean service. The merged service was named Ragnarok Online MSP.
• November 28, 2021: RO MSP was shut down.
• February 23, 2022: A new service for the Philippines, Malaysia, and Singapore was launched by Gravity Game Hub. The service is named Ragnarok Online GGH.