Police were called to Lower Stone Street at 4am, following reports of a disturbance.
Kent 999 reports a “large group of people” were involved in the incident.
The victim was airlifted to a hospital in London where he is receiving medical treatment.
Police are investigating the incident but have yet to make any arrests.
Anyone with information about the event is urged to contact Kent police.
Authorities are keen to acquire any video recordings of the incident, such as mobile phone or CCTV footage.
If you have information Kent police can be reached via 01622 604100, quoting reference 03-0185.
Alternatively Crimestoppers, an independent charity, can be contacted anonymously via 0800 555111 or www.crimestoppers-uk.org.
In a statement Kent police said: “Information is sought following a serious assault in Maidstone.
“Kent Police was called at 4am on Saturday 3 July 2021 to a report of a disturbance involving a large group of people in Lower Stone Street.
“During the disturbance, a man sustained a serious injury which is consistent with a stab wound.
“He has been airlifted to a London hospital, where he remains in a serious condition.
“Enquiries at the scene are ongoing and, at present, no arrests have been made.”
Shortly after 9am on Saturday morning the force also tweeted about the incident.
They said: “We’re investigating a serious assault which took place in Lower Stone Street #Maidstone at around 4am this morning (3 July).
“If you have any information that can help with our enquiries, call us on 01622 604100 quoting 03-0185.”
Tudor Park Golf Club, in Maidstone, warned its members about travel disruption following the event.
They tweeted: “Bottom of lower stone street – police have cordoned off road – please take an alternative route if possible.”
A number of local residents expressed their concern about the incident on social media.
Alex Hortal tweeted: “Any idea what’s going on at the bottom of upper stone street in Maidstone?
“Forensics down there and bunch of people in hazmat suits, everything completely shut off.”
Another man added: “What’s happening in Maidstone this morning? Chaos.”
Cycles UK, which runs stores across the UK, posted: “Unfortunately there had been a police incident outside our Maidstone store overnight so they are closed this morning.
“We hope to re-open this afternoon.”
More to follow…