- "This Earth is at the center of the multiverse. It's the access point to every other Earth in existence."
- —Hunter Zolomon, referring to Earth One[src]
Earth One is a universe parallel to a plethora of others, such as Earth Two. The name was coined by Martin Stein. To Earth Two citizens, Earth One is referred to as Earth Two. Also, to Earth Seventeen's citizens, it is known as Terra Prime.
After learning of the existence of parallel worlds, Martin Stein coined the world's name, "Earth One", to describe Team Flash's relative position in regards to all of the other worlds. Beginning in the early 21st century, it has become home to numerous groups of extraordinary protectors, such as the vigilante unit Team Arrow, the scarlet speedster known as the Flash and his team of allies who emerged after the explosion of the S.T.A.R. Labs particle accelerator that gave rise and prominence to superpowered metahumans, and John Constantine's group of mystical allies. Even in other times, similar such heroes operate, such as the secret mid-20th century alliance the Justice Society of America, and the time-travelling Legends.
Events (in chronological order)
- Trojan War (1258-1248)
- American Revolutionary War (1775-1783)
- American Civil War (1861-1865)
- World War I (1914-1918)
- Spanish Civil War (1936-1939)
- World War II (1939-1945)
- Battle of Saint-Lô (1944)
- Cold War (1947-1991)
- Redmond Dominator Invasion (1951)
- Somali Civil War (1991-present)
- Battle of Mogadishu (1993)
- Afghan War (2001-present)
- Alpha-Omega release (Hong Kong) (2010)
- The Undertaking (2013)
- S.T.A.R. Labs particle accelerator explosion (2013)
- The Siege (2014)
- Alpha-Omega release (Star City) (2015)
- Genesis (2016)
- Dominator invasion (2016)
- Invasion from Earth-X (2017)
- Crisis of 2024 (2024)
- Flashpoint (briefly; erased due to Barry's restoration of the timeline)
- Legion of Doom's alternate reality (briefly; erased due to the Legends' intervention)
- Anachronisms (sudden prominence throughout time as a result of the time storm caused by the Legends)
From Earth Two
- Laurel Lance/Black Siren
- Shay Lamden/King Shark
- Linda Park/Dr. Light
- Hunter Zolomon/The Flash/Zoom/Black Flash (deceased)
- Dante Ramon/Rupture (deceased)
- Al Rothstein/Atom-Smasher (deceased)
- Eddie Slick/Sand Demon (deceased)
- Harrison Wells
- Jesse Wells/Jesse Quick
- Zoom's meta-human group
From Earth Three
From Earth Nineteen
From Earth Thirty-Eight
- The Ray (deceased)
- Tommy Merlyn/Prometheus (deceased)
- Oliver/Black Arrow (deceased)
- Leo Snart
- Kara/Overgirl (deceased)
From an unknown Earth
- "Mr. Queen Is Unavailable"
- "Roy to the Rescue"
- "Down the Rabbit Hole"
- "The Sample"
- "Closing In"
- "Heroic Deeds"
DC's Legends of Tomorrow
- "Worlds Finest" (mentioned)
- "Star-Crossed" (mentioned)
Chronicles of Cisco
Freedom Fighters: The Ray
Arrow: Season 2.5
The Flash: Season Zero
Arrow: The Dark Archer
- Earth One vibrates at a lower frequency than Earth Two.
Behind the scenes
- The universe's name is spelled "Earth-1" in the synopses for The Flash episodes.