My first thought was that I had misheard. I was watching a scene in the film “Saving Mr. Banks” where Walt Disney, played by Tom Hanks, is giving a tour of Disneyland to P.L. Travers (Emma Thompson), the author of Mary Poppins, which he would dearly love to film. What I seemed to have heard didn’t make sense to me. But a tweet from @NickyD pointed out the same thing and directed me to the movie’s screenplay. That document confirms that Disney tells Travers, “In Adventureland there is a tree–this is a fun fact. A titbit … ”
Then Travers interrupts and corrects him: “Tidbit.”
Disney goes on: “… It has three million leaves, four million flowers”
The surprising thing isn’t that Travers would presume to correct the great Disney. According to the film, that is the very core of her character. Rather, it is an apparent reversal of the characters’ presumed position on the corrected point. I had thought of titbit as both a Britishism and the original form of the expression, and tidbit as a predominately American corruption.
The OED and Google Ngram Viewer gave me some nuance. The first use cited in the OED comes from 1649, is British, and is in fact tidbit, spelled a little differently: “A tyd bit, i.e. a speciall morsell reserved to eat at last.” The first titbit (also British) appears in 1697 and the last, from T.A. Trollope, in 1887: “During the singing of the well-known tit-bits of any opera.”
Ngram Viewer gives a sense of the popularity of the variants in the two countries:
The “Mr. Banks” scene takes place in 1961, at which point, according to Google, tidbit was indeed the favored version in American English and titbit in British English. Now, titbit was still relatively common in AmE until beginning a steady decline in around 1930. (Presumably, that coincided with the rise to prominence of the slang tit, referring to a [usually woman’s] breast, making titbit seem improper, albeit unfairly. British titbit began a decline of its own commencing in around 1950, possibly because by that point the anatomical tit had crossed the Atlantic.) So it’s possible that Disney, who was born in 1901 to an Irish-Canadian father, would indeed have used the term. But that seems far too convoluted a linguistic possibility for this film to make note of.
IMDB tells me that one of the screenwriters of the film, Kelly Marcel, is British, and the other, Sue Smith, is Australian, as was Travers. And it would seem that the only plausibility for the anomaly is the Australian connection. Is it the case that tidbit was and is favored in Oz, to the extent that Aussies would think of titbit as an American corruption? I await wisdom from NOOB readers Down Under.
notoneoffbritishisms.com 
For what it’s worth, there has long been a tacky British “top shelf” magazine, from way before the current obsession with celebrity and A-Z listers. It was mild by modern standards, and summarised for the 1970s:
“Titbits was a weekly that was the 70s’ dad’s equivalent to Nuts or Zoo magazine.
Sport, fags, booze, cars and women. It still makes me giggle to myself. Titbits was the first magazine to feature a glamour girl on the front cover, albeit in clothes. It was first produced by IPC and stood as a major competitor to The Sun newspaper, but was sold on to Sport Newspapers, then sold again. These days it falls more into the top-shelf category.
– See more at: http://www.doyouremember.co.uk/memory.php?memID=8947#sthash.kpgjXD4b.dpuf ”
Michael Young.
In Ulysses, Mr Bloom takes a copy of Titbits into the lavatory with him to read in the lavatory (and then uses it as toilet paper). Whether the seventies magazine was a successor to the one in 1904, I don’t know.
TIt-Bits wasn’t really like a top-shelf magazine or a men’s magazine. It was read by women much as celeb gossip mags are today. It had general interest snippets of information, human interest items and gossip and scandal about celebs, film stars and the like. I suppose it could be described as a bit saucy, scandalous and downmarket. In that sense it reminds me of the News of the World which was sold as a family Sunday newspaper but full of gossip and scandal.
Here’s a piece I found online about its origins and history:
“Tit-Bits (or to give it its full title Tit-Bits from all the interesting Books, Periodicals, and Newspapers of the World) was a British weekly magazine founded by George Newnes on 22 October 1881 until 18 July 1984,[1] when it was taken over by Associated Newspapers’ Weekend, which itself closed in 1989. The last editors were David Hill and Brian Lee.[2] Tit-Bits lost the hyphen from its masthead at the beginning of 1973.
The magazine was a mass circulation commercial publication which reached sales of between 400,000 and 600,000, with the emphasis on human interest stories concentrating on drama and sensation.[3] Short stories and full length fiction was also incorporated, including works by authors such as Rider Haggard and Isaac Asimov, plus three very early stories by Christopher Priest.
The first humorous article by P. G. Wodehouse, ‘Men Who Missed Their Own Weddings’ appeared in TitBits in November 1900.[4] “
It becomes even more interesting:
“In All Things Considered by G. K. Chesterton, the author contrasts Tit-Bits with the Times, saying: “[an author] ask himself whether he would really rather be asked in the next two hours to write the front page of The Times, which is full of long leading articles, or the front page of Tit-Bits, which is full of short jokes.” Reference to this magazine is also made in James Joyce’s Ulysses,[5] George Orwell’s Animal Farm, James Hilton’s Lost Horizon, Virginia Woolf’s Moments of Being, and H. G. Wells’ The First Men in the Moon. H. G. Wells also mentioned it in his book Experiment in Autobiography, chapter VI. The magazine is burlesqued as ‘Chit Chat’ in George Gissing’s ‘New Grub Street’.
The magazine name has survived as Titbits International.”
http://uk.ask.com/wiki/Tit-Bits
If you watch the classic Ealing comedy Kind Hearts and Coronets, in the final scene the hero, Louis Gascoyne (Denis Price), is approached on being released from prison by a rather grimy little man who introduces himself as a reporter from Titbits, and offers him money for his memoirs (which prompts Louis to recall that he has left same memoirs, which include a confession to several murders, in his cell).
Chris, to add a “titbit” of trivia, the “grimy little” journalist was none other than Arthur Lowe. Nearly twenty years later he became famous as Captain Mainwaring in “Dad’s Army”.
I’m Australian (grew up in Tasmania), and I think “tidbit” is the more common usage here. It’s what I would use at least.
As a Brit, I’d never heard “tid-bit” until I went to the States. I’ve heard it said that “tid-bit” was adopted by puritanical Americans who were uncomfortable at hearing the word “tit” being used in mixed company. I’m sure that’s completely untrue, but a good story nevertheless.
Dictionaries I’ve looked at give both forms but according to my Chambers and others, “tidbit” seems to be more American than English.
Chambers doesn’t give the etymology, presumably because the origins are obscure. Others do, in some cases a tad tentatively, based on “tid” or “tyd” meaning tender or soft. One even goes for “tid” in Old English, meaning a division of time, giving us the word “tide”, as in Eastertide, eventide, meaning time or season. From there, hey presto, a tasty morsel associated with a feast day.
It could be that it started out as “tid” but evolved in England by (mistaken) association with “tit” meaning small, or simply because it lent itself naturally to a preference for a rhyming form of the (spoken) word and the “titbit” spelling followed. Meanwhile in America they may have preferred to keep the original form, either out of fidelity to correct form or because it lent itself more naturally to American speech.
When are anatomical tits supposed to have crossed the Atlantic, and in which direction?
Anybody know why they are called Bristols?
Cockney rhyming slang. Bristol City – titty. I think it’s a reference to the football club, not the metropolitan area.
Sammy (above) has the most correct answer describing Titbits. It was a general interest down-market weekly. The readership was split more or less evenly between male and female with a leaning towards the over forties (who probably bought it through habit). I was the Art Editor of the title during the seventies and early eighties. The circulation slowly fell over the years because of competition from TV, tabloid newspapers and price rises. It was just over 700,000 when I start to work there…a quite respectable circulation for a weekly title in the UK.
As a child of the 60s, I grew up loving the snack food called “Tidbits”–could the existence of the brand name have had anything to do with the increase in that version of the term?
Another Australian here – I have the opposite experience to the other Aussie, above. It has always been “titbit” and I didn’t know about the “Tidbit” variant till I moved to the USA. I thought it was Americans trying to cut the word “tit” out in much the same was as “snigger” has morphed into “snicker” in US English.
This all makes me wonder about the expression “giving tit for tat.” I wonder where that comes from.