Killer Jaymes Todd has lost his bid to be released from jail before he is 54, after appealing his life sentence for raping and murdering Melbourne woman Eurydice Dixon in 2018.

Todd had appealed for mercy from the Court of Appeal, Victoria's highest court, after having been sentenced to life behind bars with a non-parole period of 35 years, for actions Supreme Court judge Stephen Kaye described in September as "pure and unmitigated evil".

The now 20-year-old watched Thursday's court proceedings impassively, through a videolink from prison. He did not react as Supreme Court Chief Justice Anne Ferguson read the court's reasons for rejecting his bid for his prison sentence to be reduced.

Todd's lawyers had argued his young age, guilty plea, "good character", dysfunctional upbringing, remorse, and autism spectrum disorder, meant his lengthy sentence was "manifestly excessive".