The reality TV star and criminal justice reform campaigners shared a plea to save Brandon Bernard, a 40-year-old imprisoned in Indiana, on social media.
Bernard was sentenced to death in 2000 after being found guilty of two counts of murder. At the age of 18, he was involved in the abduction and robbery of two youth ministers in Texas.
Kardashian West described the crime as “terrible” but argued Bernard’s role was “minor compared to that of the other teens involved, two of whom are home from prison now”.
She called on Mr Trump to intervene and stop the execution.
She tweeted: “Most of the time executions happen, in our names, without a lot of attention given to them.
"This is unacceptable. For the next 24 hours, I will be tweeting about Brandon and his case and why his life should be spared by @realDonaldTrump.”
Mother-of-four Kardashian West urged her followers to tweet the president asking him to act.
Campaigners have been working to save Bernard’s life, arguing that during his trial prosecutors withheld evidence that could have influenced the jury at sentencing.
They say he only occupied the “lowest rung” of the gang with whom prosecutors alleged he and his co-defendants were affiliated.
Bernard was sentenced to death for his part in the murders of Todd and Stacie Bagley. Some of his accomplices were under 18 and ineligible for the federal death penalty so received jail sentences.
However, another defendant, who was 19 at the time of the crime, was executed in September.
If Bernard is put to death, he would be the ninth federal prisoner to be executed since Mr Trump’s administration ended a 17-year pause in federal executions in July.
Kardashian West has become a prominent criminal justice reform campaigner and has met Mr Trump at the White House.
Her work led to grandmother Alice Marie Johnson being freed from prison in 2018.