Nurse Lucy Letby has applied to appeal against her conviction for murdering seven babies and trying to kill six more, a UK court spokesperson says.
Letby was last month found guilty of killing five baby boys and two baby girls at the neonatal unit of Countess of Chester hospital in northern England over 13 months from 2015, injecting the infants with insulin or air or force feeding them milk.
The 33-year-old was sentenced at Manchester Crown Court to a whole-life order last month, meaning she will never be released from prison.
Letby has filed an application for leave to appeal against her conviction at London's Court of Appeal, a court spokesperson said.
No date for any appeal has been set, they added.
The nurse's conviction, following a harrowing 10-month trial, made Letby the UK's worst serial child killer in modern history, local media said.
Letby had refused to attend her sentencing in August, which the mother of one of her victims described as a final act of wickedness.
Shortly after, the UK announced plans to give judges new powers to force criminals to attend their sentencing following a furore over several other high-profile cases where killers refused to appear in the dock.
The government has also launched a public inquiry into the case, which will look at the circumstances of Letby's crimes and consider accusations from doctors on the neonatal unit that their concerns about Letby were not heeded by senior staff.