I will be in London in September and want to do a day trip to either Oxford or Cambridge.
Which would you recommend and why?

flip a coin -- honestly. The two are very similar in atmosphere/sites/convenience from London.

Me personally -- a slight edge to Oxford (but again -- it essentially doesn't matter which you choose)

Ask 12 fodorites and each will have their own subjective favorite - and you still wouldn't know which

I'm an Oxford fan and others here prefer Cambridge. Having spent time in both, I find Oxford has more going for it, especially for a short visit, including proximity to the train station. If I were going north for a day out I'd be more inclined to stay on the train past Cambridge to Ely, beautiful small town with a striking cathedral. But I do love & recommend Oxford.

My last visit: http://www.travelgumbo.com/blog/a-day-in-oxford

Having been to both several times like janis says flip a coin - could not recommend one over the other but highly recommend going to one.

OK, I'll be the Cambridge vote. We prefer Cambridge despite (or maybe because of) living near Oxford in the past. Just a more pleasant city to visit.
You could easily combine Cambridge and Ely in a single day trip.

That said I shall be cheering for the dark blues in the bat race!

boat race!

Cambridge with the backs is prettier in my opinion and the town is less of a city than Oxford but I admit to be biased and vote light blue. Train station definitely more convenient in Oxford but it's an easy bus or taxi ride to the centre in Cambridge.

As a Tolkien fan, I chose Oxford.

Lee Ann

If it's sunny, go to Cambridge. I still kick myself for not stopping to watch a cricket game there. If it's rainy, go to Oxford. More to do indoors there.

"If it's sunny... If it's rainy..."

Sunny where, rainy when? If the OP has visited the UK before, they know that weather there is quite unlike the predictable weather in Los Altos. If not, fair warning, if it's determined that it'll be sunny, assume rain too, and vice versa.

Buses run straight past the Cambridge train station every 15 minutes or so, and stop in the city centre a few minutes later (it's not that far a walk either). Most of the ancient colleges are in a small area in the city centre, as is the Fitzwilliam Museum.

There are many independent shops in that part of the city as well, and lots of pubs and small restaurants. The backs along the river are a delight to walk on a warm summer's day.

I have gone to Cambridge, because I'm a fan of sir Isaac Newton. And I like Cambridge's quiet, pictoresque towns with its rivers and bridges.

I'll go to Oxford soon because I'm also a fan of Tolkien fan.

Your call.

might interest
http://www.fodors.com/community/euro...d-24-hours.cfm

Both if time will allow - if not then I recommend Cambridge, beautiful city with perfect picturesque places. If it's warm enough then definitely take a punt out on the River Cam, a brilliant way to see the rich history of The Colleges. Cambridge Punt Company will do private or shared tours along the river at decent prices - have a look: http://www.cambridgepuntcompany.co.uk

Cambridge - lovely botanic gardens, Fitzwilliam museum is a great smaller scale museum and the cafe does great grub for lunch. The backs of the colleges/mathamatical bridge/bridge of sighs etc all worth a look.

As mentioned above some nice independant shops and cafes - Mill Road a bit further out of the centre has great food festivals a few times a year so check to see if anything like that is on.

Walk along the river past the houseboats and the old lido at Jesus Green if the weather is nice. You can see rowers and punters without having to risk getting wet!

RM67: "Cambridge - lovely botanic gardens, Fitzwilliam museum is a great smaller scale museum and the cafe does great grub for lunch. The backs of the colleges/mathamatical bridge/bridge of sighs etc all worth a look."

Oxford - lovely botanic garden, any number of small museums and the ancient Bodleian Library, walks along the Thames and River Cherwell. Hertford Bridge or, popularly, the Bridge of Sighs.

My point, both cities have similar lists of attractions on the face of it, but having been to both more than once/many times in the case of Oxford, there is no logical reason for preference. I find the general ambiance of Oxford more to my liking and RM67 seems to prefer Cambridge. Flip a coin and see the other next time.

Oxford: And the punts too.

Just yesterday afternoon I watched them refurbishing the punt fleet beneath magdalene bridge next to the botanic gardens.

"Magdalen" Bridge in Oxford ;-)

Was my phone's fault