we were watching the olympics, and they played one of those mini bios, with him narrating about his life.  as i'm listening to him, i hear that he's nonrhotic, he does the no->nigh thing, and i *think* i'm hearing a little of the bahth/commahnd thing.  so i'm thinking he's from southeastern england, maybe london.  but then i pull up his wikipedia page to check, and it says he was born out in plymouth, devon.  so i'm thinking ok, but maybe he then moved to london and grew up there.  nope, also grew up and went to school in devon.

here is a sample of him talking:  Spoiler (click to show/hide)

https://www.youtube.com/watch?v=5mOIR3HFunw

is this a devon accent?  or is he affecting a london posh accent?  or what?

is there something in how he speaks that jumps out as southwestern england?  if so, what is it?

Its fairly standard RP accent. You get it everywhere. There's a slight rolling of r's that you get in the Southwest, but not much of it.

right, don't know how I forgot about RP...

so I'm presuming there is a regional accent for Devon which is different from RP.  guessing everyone is taught RP in school, and you get 1) some people blowing it off and continuing to speak in their regional accents, 2) some people learning RP in addition to the regional accent and then switching between registers depending on whom they're talking to, and 3) some people actually speaking RP natively just because they're so immersed in it; school, bbc, family, friends, etc.  maybe there are sort of bubbles of native RP speakers associated with educated/professional neighborhoods, sprinkled around the country.

if so, obviously Tom wouldn't be #1.  I'm tempted to say #3, because I haven't heard him switch registers at all, not even in videos with his family.

right, don't know how I forgot about RP...

so I'm presuming there is a regional accent for Devon which is different from RP.  guessing everyone is taught RP in school,

No, you're not taught RP.

and you get 1) some people blowing it off and continuing to speak in their regional accents, 2) some people learning RP in addition to the regional accent and then switching between registers depending on whom they're talking to, and 3) some people actually speaking RP natively just because they're so immersed in it; school, bbc, family, friends, etc.  maybe there are sort of bubbles of native RP speakers associated with educated/professional neighborhoods, sprinkled around the country.

if so, obviously Tom wouldn't be #1.  I'm tempted to say #3, because I haven't heard him switch registers at all, not even in videos with his family.

The "bubbles" will generally be individual families, rather than particular neighbourhoods. I have a fairly RPish accent, but with traces of South-East London/NW Kent, and it varies depending on how much I've had to drink- "wiv" rather than "with", glottal stops, that sort of thing, all crop up more after I've had a couple. Other people who went to the same school as me have a much stronger accent than I do.

RP???

(Ranting Poser was my first guess)

Recieved Pronunciation. Basically the stereotype BBC accent.

to americans, it's the stereotypical proper elite english accent, which is probably used by half the english characters we see in american tv and movies, even though it is only spoken by a small subset of the population (3%, by one estimate).  the kind of english person that pronounces "bath" as "bahth" and "stupid" as "styupid".  ........  not working class " 'ello swee'ie".  nor Christopher Eccleston ' s regional accent from "oop north".  and cerrrrtainly not sco'ish.

right, don't know how I forgot about RP...

so I'm presuming there is a regional accent for Devon which is different from RP.  guessing everyone is taught RP in school, and you get 1) some people blowing it off and continuing to speak in their regional accents, 2) some people learning RP in addition to the regional accent and then switching between registers depending on whom they're talking to, and 3) some people actually speaking RP natively just because they're so immersed in it; school, bbc, family, friends, etc.  maybe there are sort of bubbles of native RP speakers associated with educated/professional neighborhoods, sprinkled around the country.

if so, obviously Tom wouldn't be #1.  I'm tempted to say #3, because I haven't heard him switch registers at all, not even in videos with his family.

The Devon accent has rhotic r's but some people lose it when they leave.

And the rhotic r line is moving and the areas shrinking.  Scotland is still OK though, but it's almost gone in Lancashire.  And in Northumberland the line is now at the border.

Also, with Tom Daley, there's a bit of conscious camp of course, on top of the rp.

to americans, it's the stereotypical proper elite english accent, which is probably used by half the english characters we see in american tv and movies, even though it is only spoken by a small subset of the population (3%, by one estimate).  the kind of english person that pronounces "bath" as "bahth" and "stupid" as "styupid".  ........  not working class " 'ello swee'ie".  nor Christopher Eccleston ' s regional accent from "oop north".  and cerrrrtainly not sco'ish.

"Lots of planets have a north"

it's been fun watching the different doctors and trying to learn something about accents. Tennant was a scot acting with an English accent, smith was english acting with an English accent, Capaldi is a scot acting with a scottish accent, and Eccleston was just from manchester.