"Well, I wouldn't say that I started it (rock 'n' roll), but I don't remember anyone else before me playing that kind of stuff."
Domino was born and raised in--where else?--New Orleans.
Domino started playing pianos in bars when he was about 14 (apparently he wasn't carded.) He was a little older than that when he was hired to play piano for the Solid Senders. It was the leader of that band, Billy Diamond who gave the young Antoine (he was of French-Creole descent) his nickname "Fats" after piano players Fats Waller and Fats Pichon. And, yeah, Domino had a hearty appetite, so that had something to do with it, too.
Domino came to the attention of trumpeter-turned-record producer Dave Bartholomew, who signed him to the Imperial label. Together the two men wrote, and Domino sang and played the piano on, a 1949 recording called...
..."The Fat Man". Domino also supplied the "wah wahs".
Domino, with Bartholomew's help, had a string of hits throughout the 1950s.
"Ain't That a Shame". Domino's first Top 10 hit,in 1955. Note the actual record had the WRONG title!
"Blueberry Hill", written in 1940, had previously been recorded by the Sammy Kaye Orchestra, Gene Krupa, Glenn Miller, Gene Autry (!), Jimmy Dorsey, and Louis Armstrong, but it became (most likely) forever identified with Domino, starting in 1956, when it went all the way to #2. It was his biggest hit.
"I'm Walkin'", 1957.

So why does most everyone think that rock 'n' roll started in the 1950s? Well, after World War II, swing, boogie woogie, whatever you call it, fell out of favor. Jazz, in the form of bebop, became intellectualized (whether performers such as Parker saw themselves as intellectuals or not.) As a now Depression-free and war-free America became a much more mellow place, so did its listening habits. Artists such as Doris Day, Patti Page, Perry Como, and Johnny Mathis ruled the airways. I personally don't have a problem with their kind of music (which is now almost extinct) but had I been a teenager in the 1950s, I probably would have found it boring, as did many teens at the time. So when the new/old music now called rock 'n' roll came along, kids found it new and exciting, and THAT'S what I think Domino meant.
Of course, in the coming decades, music would become even more novel and exciting, even revolutionary, probably too revolutionary for the likes of Fats Domino, who fell out of favor. He nonetheless earned a living on the nostalgia circuit, and, as I understand it, continued to keep fans satisfied.