In Sci-Fi world, Time can re-written. Lots of Sci-Fi works exploit time travel to bring back the people once dead, either in the same timeline or in a different timeline.
I asked a similar question: Which Sci-Fi work introduced the idea of "Protecting Child-self"?
In such Bootstrap Paradox situation, the protected ones never die. On the other hand, this question advocates about the situation in which one actually dies and he is brought back to life by Time Travel (Here, Bootstrap Paradox may or may not be involved after the guy is saved).
For example, the first such idea I encountered was in Captain Vyom S01E32 (1999). In it, the hero died after a guy put on a poisonous ring on his finger and shook hand with the hero. His friends acted quickly to travel back in time and replace that poisonous ring with normal one. And, the hero didn't die this time.
(jump to 5:45; English subtitles are available)
In The Flash (2014) TV series,
Barry's mother was dead. Flash travelled back in time to save her. Reverse Flash was confident that she could be saved and future Flash told past Flash to not do that. It means that her mother could be saved.
So, this concept can be seen here.
Honorable Mention: Doctor Who. This TV series has used it too much. Be it Rose saving her father from death or The Doctor saving Mars landers from death, all can be considered example.
Which Sci-Fi work introduced the idea of "Resurrection of Dead by Time Travel"?