Ariana Grande performed at the Macy's Thanksgiving Day Parade this morning (28.11.13).

The 20-year-old star sung 'Last Christmas' from her float while clad in a thick coat and large earmuffs to try and keep warm in New York City.

She tweeted: ''Happy Thanksgivinggg my loves...Wishing you a beautiful holiday with your families and loved ones. I am so thankful for you. (sic)''

Elsewhere in the parade, talk show host Jimmy Fallon joined the 'Sesame Street' float with Elmo, Cookie Monster, the Count, and Big Bird, who all sang 'Somebody Come and Play'.

Jimmy had earlier joked on Twitter: ''I'm on the 'Sesame Street' float in the parade ... But it'll be awkward when Big Bird asks, 'What're you having for dinner?' ''

Meanwhile on the other side of the US, sitcom star Neil Patrick Harris and Disney star Bella Thorne did their bit to give back last night (27.11.13) by joining hundreds of other volunteers to help to feed Thanksgiving dinner to the homeless at Los Angeles' LA Mission.

Neil - who was working in the kitchen - tweeted: ''Prepping the turkey for @TheLAMission 's annual thanksgiving meal. A wonderful organization. #thankful.

''Super grateful to @MVoltaggio and all the other amazing chefs for lending their time and brawn. I was honored to be included. (sic)''

Bella was joined by her boyfriend, Tristan Klier, and helped to give out meals to the homeless.

Many more celebrities took to social media to send out their best wishes to all.

Lady GaGa tweeted: ''Happy Thanksgiving little turkey+tofurkey monsters, I love you with all my heart and thought all day about how grateful I am to be a performer in this life, writing you songs and singing to you year after year! #thankful4monsters (sic)''

Country star Carrie Underwood wrote: ''I have much to be thankful for...Family, friends and fans! Hope you all have a blessed day. Lots of love from me to you! #HappyThanksgiving.(sic)''