Both are right.
This is how the Oxford dictionary entry explains the usage: The spellings adviser and advisor are both correct.
Adviser is more common, but advisor is also widely used, especially in North America.
Adviser may be seen as less formal, while advisor often suggests an official position
english.stackexchange.com/users/264/Manjima
I just happened to come across this issue writing a final exam for a course in international financial derivatives regulation.
(For those of you who don't know what that is, it's what you do in purgatory.)
Both spellings are correct.
In general,"adviser" is the preferred spelling, especially in the UK.
"Advisor" carries a connotation of someone whose professional capacity is to give advice.
On that basis, and since my course had a strong focus on American regulation, I changed "adviser" to "advisor" regarding "very-high-net-worth individuals ... who tend to employ the service of sophisticated advisors to assess and manage their risk.
" If you want to know my sources, just google "adviser or advisor" like I did and you'll get them all.
Can't resist taking a swipe at the obiter on "amount" vs. "number" in the media.
My two fields are English Literature and Law.
Like Law, English grammar is based on rules which must be faithfully applied in order to preserve a unified fabric, but like Law, English is (forsooth) a living language.
It lives and is preserved our media of communication.
When the editors of the OED want to know what the "correct" usage of a certain term was in the 19th century, they turn to ... the media!
I'm the first to be a stickler for good usage, but don't overdo it.
english.stackexchange.com/users/64925/Pink Floyd
Advisor should be the preferred spelling, consistent with other official titles: actorconvenorcoordinatoreditorregulator
I am a professional general and scientific editor with over 40-years experience.
The tragedy is that the media often perpetuates mis-spellings and mis-use, witness the current use of 'amount' for every quantitative description, e.g. amount [sic] of people, rather than number of people.
english.stackexchange.com/users/47379/Marion
The nearest reference book to my computer, the "Oxford Writers' Dictionary" , says advis/er not -or; ory
english.stackexchange.com/users/None/
I am an academic advisor.
I have seen the term used both way, and after thinking about it, I think that the distinction between one who is a professional advisor and once who gives advice on an informal basis should be maintained.
I had previously called myself an "adviser.
" Now I am an "advisor."
I should point out, however, that there is no difference in pronunciation.
I would not want to assert some distinction that does not exist, as in those ridiculous advertisements that over-articulate the last syllable in "realtor.
"
Regardless of spelling, the ultimate vowel is still a schwa.
english.stackexchange.com/users/65181/user65181
In Australian Financial Services, the legislation uses the spelling Advis e r
so that is the source of truth in Industry.
In regular Australian vernacular both spellings are used.
english.stackexchange.com/users/15280/hawkeye
While in general adviser and advisor mean the same thing, it appears in at least one context that is not true.
In Canadian banks financial advisers are subject to regulation, but financial advisors are not .
english.stackexchange.com/users/695/DJClayworth
I work for a financial services provider and we deal with "Financial Advisors" all the time. Increasingly, I'm seeing people send emails and so forth with the term "Financial Adviser" and the terms adivsor and adviser seem to be increasingly interchangeable. Which then raises the question: what is the difference between adviser and advisor ?
What's the difference between "adviser" and "advisor" -- are both interchangeable?
english.stackexchange.com
<meaning><orthography><suffixes><agent-noun-suffix>
english.stackexchange.com/questions/2714
english.stackexchange.com/users/235/lomaxx
The words "adviser" and "advisor" are both considered to be correct and have the same pronunciation. However, there is disagreement about which should be the preferred spelling. That said, "adviser" may be perceived as less formal whilst "advisor" may suggest an official position. Both are right but adviser may be seen as less formal, while advisor often suggests an official position 
The words "adviser" and "advisor" are both considered to be correct and have the same pronunciation. However, there is disagreement about which should be the preferred spelling. That said, "adviser" may be perceived as less formal whilst "advisor" may suggest an official position. Both are right. In general,"adviser" is the preferred spelling, especially in the UK, but advisor is also widely used,  especially in North America. the  "Oxford Writers' Dictionary" , says    advis/er   not  -or;  ory   The distinction may be between one who is a professional advisor and once who gives advice on an informal basis.
Both spellings are correct.   In general,"adviser" is the preferred spelling, especially in the UK.  "Advisor" carries a connotation of someone whose professional capacity is to give advice.   Both spellings are considered to be correct, although there may be subtle differences in their usage. "Adviser" may be seen as less formal or professional as "advisor". Furthermore, there seem to be regional differences, with "advisor" being more common in North America. However, in Canada, "financial advisers" are subject to regulation whereas "financial advisors" are not.
Both are right but adviser may be seen as less formal, while advisor often suggests an official position  S0: Advisor should be the preferred spelling, consistent with other official titles.  In Canadian banks financial advisers are subject to regulation, but financial advisors are not .
Both are right. In general,"adviser" is the preferred spelling, especially in the UK, but advisor is also widely used,  especially in North America. the  "Oxford Writers' Dictionary" , says    advis/er   not  -or;  ory   Advisor should be the preferred spelling, consistent with other official titles:  actorconvenorcoordinatoreditorregulator   The distinctionmay be between one who is a professional advisor and once who gives advice on an informal basis should be maintained.
Both spellings are considered to be correct. Adviser is more commonly used outside of North America. "Adviser" may be perceived as less formal or professional than "advisor". In Canada, "financial advisers" are subject to regulation whereas "financial advisors" are not.