Steve Bouquet, a 54-year-old security guard, attacked the pet cats over a nine-month period near his home address, beginning October 2018.
Nine of the cats were stabbed to death, while a further seven survived their injuries. Bouquet, who denied the charges of criminal damage and possession of a knife in a public space, was found guilty at Chichester Crown Court on Wednesday following an eight-day trial, police said.
The jury heard how the pet owners had incurred thousands of pounds in veterinary bills following the stabbings.
He will be sentenced on July 12.
Following reports of the stabbings, police were initially at a loss as to who was responsible.
"There were no witnesses to the savage acts and there was no indication as to who was responsible," Detective Inspector Chris Thompson said in a statement.
But the case took a turn in May 2019 when Bouquet was caught on CCTV stroking and then attacking a 9-month-old cat called Hendrix, who later died of its injuries.
"The [Hendrix's] owners discovered a trail of blood leading from the passageway to their home and then noticed a CCTV camera nearby. This had been set up by a neighbor whose own cat had suffered a similar fate, having been stabbed and killed a year before," Thompson said.
"We examined the footage and discovered that it had captured Bouquet stooping to stroke the cat before taking something from his rucksack and making a sudden jerk towards it."
Thompson described it as a "turning point" in the police investigation.
Two days later, on June 2, 2019, officers arrested the suspect and found a knife with cat DNA on the blade in his house.
Thompson added that police found evidence on Bouquet's computer that he had "repeatedly" visited a website about lost cats in the city and had viewed "numerous" videos of dogs killing cats.
Bouquet told police, who also found two photographs of dead cats on his devices, that he liked cats.