Emergency services were called at 14:50 BST on Tuesday to a river at Aberglaslyn, near Beddgelert.
Formal identification is expected to take place later today. Specialist police are supporting the man's family.
Ch Insp Mark Armstrong said: "Our sympathies go out to the family and friends of the person involved."
He said the operation to recover the body had been complex and involved police, North Wales Fire and Rescue Service, Aberglaslyn and Ogwen mountain rescue teams and the regional police underwater search teams.

However, with today's decision to recommend a third runway at Heathrow, this government has arrived at a point that its predecessors failed to.
From beating ourselves up for not building anything, we are suddenly building everything. Heathrow was chosen because of the extra boost it gives to the UK economy, but it is not the only mammoth project out there.
After a last minute wobble, the Â£18bn Hinkley Point nuclear power station has been given the green light, while the biggest of them all is coming down the track fast.
Construction on the Â£42bn HS2 high-speed rail line from London to the North is scheduled to begin next year. And that is probably not all.
The Chancellor, Philip Hammond, has hinted he may reveal some moderate government borrowing to fund targeted infrastructure spending in his Autumn Statement next month. It is enough to make the Victorians sit up and take notice.
If projections for a fairly sharp post-Brexit slowdown in the economy next year are correct, we may need this spending boost.
Yet if these projects proceed on time, there is something else we will need: people to build it all. With unemployment close to historic lows, it is not clear we have enough.
As the Victorians did, it seems very likely we will need to look abroad to find the workers for what some say promises to be a golden age of infrastructure. And that, post-Brexit, will present a political rather than an engineering challenge.

Lives were lost across five provinces, according to the National Flood and Storm Control Agency, quoted by the Associated Press.
In Quang Ngai province, flood waters reportedly rose above a previous peak recorded in 1999.
A tropical depression has dumped rain on the country.
Earlier in the week, at least 13 people died and 81 were injured when Tropical Storm Haiyan made landfall in north Vietnam after wreaking havoc in the Philippines.
There has been disruption to the coffee harvest and bean drying in Vietnam's central highland provinces, Reuters news agency reports.
The country is the world's top robusta coffee producer, accounting for around 17% of the world's output.
Flood waters have started to recede in some areas, allowing residents to return and begin digging out their homes, officials said.
Binh Dinh Province reported the highest number of deaths, followed by Quang Ngai, the official Thanh Nien (Young People) newspaper reports.
Bui Thi Thanh Chuyen, a woman in Binh Dinh, told Vietnamese state TV on Saturday she had rushed home to try and help her mother, who was trapped in her house.
"All I heard [on the phone] from my mother was 'Help me, daughter' before the connection was cut off," she said.
"I rushed here to try to help her but I cannot cross the flood to the house."
In the Danang area, villager Vo Ngoc Nghiem described the speed of the disaster: "We are familiar with floods every year but this time it rose so quickly that we had no time to cope with it.
"We weren't warned about the reservoir release. The children were at school and they were stranded there."
Some 100,000 houses were submerged and roads were closed and some national train services cancelled.
Flood waters rose quickly after 15 hydro power plants opened their sluice gates as a safety measure.
Earlier reports on the flooding gave a slightly higher estimate for deaths.
A body has been recovered in the search for a canoeist who got into difficulty in Snowdonia, police have said.
[NEXT_CONCEPT]
We have a long way to go before the we see the proverbial shovels in the ground - there will be legal and planning challenges aplenty to come.
[NEXT_CONCEPT]
Flooding and landslides in central Vietnam have left at least 28 people dead, nine missing and some 80,000 homeless since Friday.