A former boxing world champion, Amir Khan had written on @amirkingkhan from Stanley Island in New York: "Wishing you a magical and blissful holiday! Merry Christmas. A#khanfamily."
Amir, 33, had shared an Instagram picture of him, his wife Faryal Makhdoom, 28, and their two children, Lamaisah, 5, and Alayna, 20 months, wearing matching pyjamas and posing in front of a decorated tree.
It had got 395 retweets and 10.4K likes.
Amir was flooded with abuse from trolls who maintained that as a Muslim, he shouldn't be acknowledging Christmas.
Amir again tweeted: "So shocked by all the hate I'm getting on my Twitter & instagram for wishing everyone Merry Christmas and posting a picture with my family in Christmas outfits. Just want to tell those people 'I don't give a f**k'."
It got 5.6K retweets and 67.3K likes as his fans tweeted messages of support.
One fan wrote: "Fair play mate. I celebrate it too."
"I became a Muslim 31 years ago, and always look forward to celebrating Christmas with my large Christian family at my parents house just as they enjoy celebrating Eid with us. Sharing and celebrating together is what unites us and removes the divide/hate we see in society," wrote one Twitter user.
"Well done, Amir," said one fan.
"You are allowed to celebrate Christmas as you wish. I hope you and your family had a lovely time," read one post.
One tweet read: "Look at your language, you are also a role model for some youngsters, Just LOL."
Amir, of Pakistani origin, has in the past talked of his wish for greater acceptance of his faith in England. In 2009, he said that he would try to fix things between the Asian and the English communities.
( With inputs from IANS )