Luka Rocco Magnotta, 29, offered little resistance when he was picked up in an Internet cafe in Neukoelln, a working-class district of the German capital, saying simply, "You got me," said a police spokesman.
Canadian authorities said they were working on documents needed to secure Magnotta's extradition from Germany, after a days-long global manhunt that started in Montreal and shifted to Paris before finally ending in Berlin.
"I can confirm that the person arrested was the wanted Magnotta," the Berlin police spokesman told AFP.
"At 1:30 pm, a witness stopped a police car in the Karl Marx Strasse and said that he had recognised a criminal in an Internet cafe. ... Officers then went directly to the cafe," the spokesman said.
They had little difficulty overpowering and arresting the suspect, he said. "It went very quickly."
Interpol had issued a Red Notice wanted-persons alert for Magnotta, also known as Eric Clinton Newman and Vladimir Romanov, to its 190 member countries after a video purportedly showing the gruesome murder surfaced online.
In the video, which Canadian police have reportedly said shows the crime, a man repeatedly stabs another man with an ice pick and dismembers him, as a song from the soundtrack of the film "American Psycho" plays in the background.
The murder first came to light when police in Canada said last week that a human foot had been sent to the headquarters of the country's ruling Conservative Party.
A hand was later found in the mail at an Ottawa post office, and a torso was discovered in a suitcase in a pile of garbage not far from Magnotta's apartment in Montreal, where blood stains were found in multiple places.
Canadian police believe the remains belong to Lin Jun, a Chinese student who was dating Magnotta, and who was last seen on May 24th.
In Berlin, one witness told the online version of Spiegel magazine that Magnotta, who was wearing sunglasses and a black hooded sweatshirt, was reading stories about himself in the cafe.
His "French accent" first aroused suspicions among cafe employees, who then recognised him from media pictures.
He was not carrying identification but confirmed his identity to authorities, a police spokesman told Spiegel.
The arrest in Berlin brought to an end days of cat-and-mouse with French authorities who had been tracking Magnotta since Canadian investigators said he had boarded a France-bound plane on May 26th in Montreal.
With the help of Magnotta's cell phone signal, police had traced him to a hotel in the Parisian suburb of Bagnolet which they visited Saturday on a tip-off from a witness, a police source said Sunday.
In the hotel room, where police found items such as pornographic magazines and airsick bags bearing the logo of the airline on which Magnotta traveled from Canada to France, the source said.
The hunt then turned to an international bus station in Paris on Monday, as police began checking whether Magnotta fled France via Eurolines, which operates buses throughout France and Europe.
A French police source said that Magnotta had left France on Thursday on a bus for Germany, based on an analysis of footage from video surveillance cameras from the station that was completed on Monday.
Magnotta has a history of trying to disappear.
In addition to having had plastic surgery on his face -- apparently to look more like James Dean -- he often wears lipstick and makeup, has dyed his hair and worn wigs, and sometimes dresses up as a woman.
Described as handsome and narcissistic, Magnotta, who naturally has black hair and blue eyes, has also changed his name and used several aliases.
He made a 2009 posting on the Internet offering advice on how to vanish and never be found.
"A minimum of four months is really necessary to carry out the heroic actions necessary to leave your old life behind," he reportedly wrote.
He said a person must withdraw from all social circles, possess two sets of false identification papers, convert all assets to cash and then take a bus to a chosen destination, after selling a car somewhere else to mislead police.
In Canada, a justice ministry spokeswoman said they were working to submit a formal extradition request as required under the treaty it has with Germany.
The spokeswoman, Julie Di Mambro, said in a statement that officials were working "to prepare the materials in support of the request," adding that Magnotta was expected to appear in a Berlin court on Tuesday.
Montreal police said Monday that Magnotta could be responsible for other unsolved crimes, without offering further details.
Magnotta, a one-time supporter of white supremacists, posted a video online of two kittens being suffocated in a plastic bag, according to the Ottawa Citizen newspaper.