Queen Elizabeth and the Duke of Edinburgh attended Sunday Service at Crathie Kirk in Scotland yesterday.
The Queen today, arriving to church at Balmoral. #queen #balmoral #vacations http://t.co/VxE7c3mYOH—
RAUL GARCIA (@RAULGARCIADIEZ) August 24, 2014
While it is difficult to say for certain, I strongly suspect she wore modified (smaller brim) version of this hat:
Designer: Philip Somerville
Previously Worn: July 11, 2006; March 17, 2006
Photos from social media and Getty as indicated
A close-up pic I have just found, Courtesy of: https://twitter.com/RAULGARCIADIEZ and I think the hat might have been moderated as the brim is abit smaller than the debut in Singapore:

https://pbs.twimg.com/media/Bv1I4yfIEAI2F9v.jpg:large
But after further look at the photo, with the feathers/ giant flowers on the brim I think it could even be a new hat made for the green outfit above? HM has been known to have an alternative hat options for some of her outfit as we can see in some of your blog entries.
Good call, Lex. The brim has certainly been altered (something we’ve seen a few times before with Her Majesty) or this is an entirely new hat. Good catch!
Trust HM to give us a proper hat during all the royal vacation time! And this is a nice one for her!
Looks as though there is a fair amount of feathery trim on the side so I too am thinking that it is the hat proposed by Hat Q. Her Majesty loves wearing green…..and looks very good in it too. Thanks.
You are probably right, HatQueen, but it did occur to me that it could be this one http://www.glamour.com/images/fashion/2014/04/queen-elizabeth-buckingham-palace-garden-party-umbrella-2011-h724.jpg
Initially, I also thought it might be this Rachel Trevor Morgan hat. If you look at the brim shape, however, it is the same as the Somerville hat. If you look beyond the shadows in the car, the brim size also looks to be the same as the Somerville hat.
Congratulations on locating this photograph. Seems difficult to come across the Queen at church this summer. (Maybe she’s afraid photographs will swing the Scottish independence vote the wrong way.)
Of the Queen’s recent (fort 10-15 years) bright green outfits seen in public, this hat from Singapore probably is it. The only complication is that the brim in the recent photograph looks smaller than in the old photo. Hat could have been modified, of course. From the wrinkling of the sleeve in the current photo, it looks as though she’s wearing a jacket. She didn’t wear a jacket in either old photograph, but I’m sure there’s always been a jacket or coat for this outfit. Nice color.
The jacket matching that dress has been worn a few times, although never with a hat.
It’s a rather smart ensemble. The Queen looks great in green.
I wondered whether this jacket was part of the green outfit shown above from 2006. The different lighting makes is to hard to know for sure.
Then there’s this outfit (at least the jacket’s different and again never has been worn wit h a hat to my knowledge)
Lex’s recently added close-up of the hat from last Sunday does show it’s a different or a remade hat from the one in 2006, but the jacket in Sunday’s photo does look like the one you’ve shown above.
It’s a fab color for HM! Wonderful for this time in summer season too! I wonder if she has clothing sent up to Balmoral in advance of their getting there? Surely most all her wardrobe is well planned in advance with some digression for the date of course going to HM.
It’s really a pity that many good old hats in the wardrobe always got to be worn at Church, especially in Crathie Kirk and as usual, they do go off without any media coverage!!