December 7, 2018

William F. Oplinger
Executive Vice President and Chief Financial Officer
Alcoa Corp
201 Isabella Street, Suite 500
Pittsburgh, PA 15212

       Re: Alcoa Corp
           Form 10-K for Fiscal Year Ended December 31, 2017
           Filed February 26, 2018
           File No. 1-37816

Dear Mr. Oplinger:

      We have reviewed your filing and have the following comment. In our
comment, we
may ask you to provide us with information so we may better understand your
disclosure.

       Please respond to this comment within ten business days by providing the
requested
information or advise us as soon as possible when you will respond. If you do
not believe our
comment applies to your facts and circumstances, please tell us why in your
response.

       After reviewing your response to this comment, we may have additional
comments.

Form 10-K for Fiscal Year Ended December 31, 2017

Item 6. Selected Financial Data, page 52

1.    In your selected financial data and your results of operations discussion
for your
      segments, you present certain amounts, such as "average realized price
per metric ton of
      primary aluminum", "average cost per dry metric ton of bauxite", "average
cost per metric
      ton of alumina" and "average cost per metric ton of primary aluminum".
Please disclose
      the numerators and denominators used to compute each amount and reconcile
the
      numerators to amounts presented in your financial statements.


        We remind you that the company and its management are responsible for
the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action
or absence of
action by the staff.
 William F. Oplinger
Alcoa Corp
December 7, 2018
Page 2

        You may contact Linda Cvrkel at (202) 551-3813 or Rufus Decker,
Accounting Branch
Chief, at (202) 551-3769, if you have any questions.



                                                        Sincerely,
FirstName LastNameWilliam F. Oplinger
                                                        Division of Corporation
Finance
Comapany NameAlcoa Corp
                                                        Office of Beverages,
Apparel and
December 7, 2018 Page 2                                 Mining
FirstName LastName