|A character from Stargate Atlantis|
|This character is part of an alternate timeline|
|Planet of origin||Earth|
|Affiliation||Alternate Atlantis Expedition|
|Out of Stargate universe information|
|Portrayed by||David Nykl|
|First appearance||"Before I Sleep"|
This version of Dr. Radek Zelenka was from an alternate timeline where the Atlantis Expedition team members were flooded inside an underwater Atlantis. He escaped with Dr. Elizabeth Weir and Major John Sheppard, but was killed when he went back 10,000 years in time.
The background of the alternate Zelenka is the same than the main reality counterpart until they reach Atlantis in 2004. He eventually escaped inside a time Jumper with Dr. Elizabeth Weir and Major John Sheppard. The city didn't have a fail-safe mechanism and remained at the bottom of the sea. Suddenly the jumper jumped back in time 10,000 years ago, in the middle of a battle between the Wraith and the Lanteans. The time jumper was shot down and Zelenka and Sheppard were killed in the process. Only Weir survived (SGA: "Before I Sleep").
- Radek Zelenka does not appear in "Rising", Part 1. His first appearance is in "Thirty Eight Minutes". Yet he is supposed to be already here, part of the Atlantis expedition.
- Radek Zelenka, the main reality counterpart