Multiple 911 calls came in from neighbours and passersby in the area of the 31400 block of Springhill Court starting around 8:40 pm PT., Abbotsford police said.
Const. Ian MacDonald said the callers all told dispatchers roughly the same thing.
"The initial reports were saying, essentially, that man was stabbing people with a knife," he said.
Paramedics and firefighters responding to the area found four injured adults, some with serious stab wounds, and took them to hospital.
Police located the suspect in a basement suite and took him into custody.
MacDonald said forensic experts have been brought in and the investigation is ongoing.
All four victims are reported to be improving Sunday morning.