With more than 3,000 'Santas' from across the country, the "Santa Hustle Race" also drew participants all the way from South Africa and Britain.
Flanked by rundown Spanish-style flats, Galveston's dilapidated Old City Square was literally a sea of red, with most of the crowd wearing red shirts, red hats and white beards.
Some boasted gaudy costumes, some were topless to show their muscles and some brought pet dogs dressed in Santa costumes.
Santas of all colours and races gathered at the starting line in the square, trying to elbow their way to the front. Toddlers in their prams looked at the crowds curiously and grannies bantered with old acquaintances.
The event was divided into a half-marathon and a five km race. Half-a-dozen rounds of runners took part in the five km race, running or walking their way through the city centre.
Another 1,000 runners ran the half-marathon along the sullen, wavy sea.
A joyous jogger Mark Herrman, 36, said: "I love running. I love the sea. I enjoy my time here, Merry Christmas!"
Some brought pet dogs dressed in Santa costumes.
However, 28-year-old Sean from the Texas capital Austin, was more keen on the race.
"My result is 24 minutes and two seconds," he breathlessly told Xinhua at the finishing line of the five km race.
Organised by Illinois based Adrenaline Sports Management, the one-day event would also be held in five other US cities, including Chicago and Indianapolis.
With outrageous decorations, festive music and a large after-party offering a buffet of food and drinks, the event has won many hearts since its debut last year.
Standing in front of a huge ballooned Santa Claus, volunteer Katherine Manning explained why so many were fond of the race.
"It's competitive but it's also relaxing. Everyone in town shows up. And you talk with people. You have fun. That's Christmas, isn't it?"