Has anyone survived going over Niagara Falls?
Yes, people have survived going over Niagara Falls, but it's incredibly rare and almost always a suicide attempt or a reckless stunt. The survival rate is less than 1% due to the 170-foot drop, the pounding water, and the rocks below. The most famous survivor is Roger Woodward, a 7-year-old boy who went over in 1960 wearing only a life jacket after a boating accident—he survived with just a concussion and scrapes. Since then, only a handful of others have lived, like Kirk Jones in 2003 (no safety gear, broke ribs) and a few who used barrels or inflatable balls, but those are illegal and you'll be charged with a crime and fined heavily.
If you're asking because you're curious about the daredevil history, skip it. The falls are a death trap, and the park police and Niagara Parks Commission patrol constantly. Even standing on the edge of the railing is dangerous—people die every year from slips or bad photos. If you want a thrill, take the Maid of the Mist boat tour ($28.25 CAD per adult) or the Journey Behind the Falls attraction ($24.50 CAD) to feel the mist and roar safely. Don't be an idiot; the falls don't care about your GoPro.