The party on Wall Street is over, and the holidays aren’t going to change that.

Banking company Morgan Stanley – having weathered a financial crisis that crippled profits and took its shares on a wild roller-coaster ride – has cancelled all plans for Christmas festivities this year, according to an internal memo distributed Friday that was obtained by The Post.

Christmas parties are a big deal at banks – a chance to blow off steam after a year’s worth of unbridled dealmaking – so it’s no small issue for top brass to cut them out.

After months of dreary headlines about layoffs and bankruptcies at competing banks, Morgan bankers lamented to The Post about the kibosh put to the year-end bashes, which now add to the insult of their nonexistent bonuses.

Nevertheless, the soured economy is poised to take a heavy toll on charities and nonprofit groups “that depend explicitly on donations, many from the financial-services sector,” Tom Nides, Morgan’s chief administrative officer, said in the memo.

“To help ease that pressure, we have asked all divisions to forgo their firm-sponsored holiday parties this year and instead help us apply those designated funds toward helping those most in need,” Nides wrote.

Morgan’s sober move follows similar measures at rivals including Barclays, which last month informed employees – including those corralled from its acquisition of Lehman Bros.’ North American business -that the crisis was forcing firms to rethink the idea of spending company cash for a big party.

Media reps at Barclays and Morgan declined to comment.