Police were called to reports that a man had suffered a knife wound in Hanover Street at about 4am on Sunday.
He was taken to hospital by paramedics but died later from his injuries, Merseyside Police said.
The force has appealed for witnesses to come forward.
The street where the victim was found remains closed as officers continue their forensic investigation.
Detective Superintendent Lee Turner said: “Knife crime will not be tolerated in Merseyside and those caught carrying a weapon will be brought to justice.
“Carrying or using any dangerous weapon does not offer protection and in fact often puts you and those around you at more risk.
“These weapons can have severe consequences and we will not stand for this criminal behaviour.”
It comes after a 17-year-old boy was shot dead in Southwark, south London on Saturday evening.
Meanwhile, Merseyside Police are hunting a bicycle-riding gunman wearing a hi-vis jacket after a fatal shooting near St Helens.
John Kinsella, 53, died after emergency services were called to reports of a “firearms discharge” in Rainhill Stoops on Saturday morning.
The suspected gunman – who is believed to have been riding a mountain bike – is described as being around 6ft tall, of slim build and wearing dark clothing and a hi-vis jacket.