FIRST AMENDMENT

Exhibit 10.1

FIRST AMENDMENT

FIRST AMENDMENT, dated as of September 13, 2013 (this “Amendment”), to the Amended and Restated Credit Agreement, dated as of June 15, 2012 (as amended, supplemented or otherwise modified from time to time, the “Credit Agreement”), among Domtar Corporation (the “Parent Borrower”), Domtar Paper Company, LLC (the “Subsidiary Borrower”), Domtar Inc. (the “Canadian Borrower”), the Additional Borrowers from time to time party thereto (each an “Additional Borrower” and, together with the Parent Borrower, the Subsidiary Borrower and the Canadian Borrower, collectively, the “Borrowers”), the banks and other financial institutions or entities from time to time parties (the “Lenders”), JPMorgan Chase Bank, N.A., as administrative agent (in such capacity, the “Administrative Agent”) and the other agents party thereto.

WITNESSETH:

WHEREAS, the Parent Borrower has requested that amendments be made to the Credit Agreement as provided herein; and

WHEREAS, the Administrative Agent and the Lenders are willing to effect such amendments, but only on the terms and conditions set forth herein.

NOW, THEREFORE, the parties hereto hereby agree as follows:

I. Defined Terms. Terms defined in the Credit Agreement and used herein shall have the meanings given to them in the Credit Agreement.

II. Amendment to Section 1.1 (Defined Terms) of the Credit Agreement. Section 1.1 of the Credit Agreement is hereby amended by amending and restating the definition of DDHI FSHCo Condition in its entirety to read as follows:

“DDHI FSHCo Condition”: DDHI has no Indebtedness or other material obligations payable to any Person other than a Global Group Member or a Governmental Authority.

III. Conditions to Effectiveness. This Amendment shall become effective on the date (the “Amendment Effective Date”) when the Loan Parties, the Administrative Agent and the Required Lenders shall have executed and delivered this Amendment to the Administrative Agent.

IV. General.

1. Representations and Warranties. To induce the Lenders to enter into this Amendment, the Loan Parties hereby represent and warrant to all of the Lenders as of the Amendment Effective Date (after giving effect to this Amendment) that:

(a) This Amendment has been duly executed and delivered by each Loan Party and constitutes a legal, valid and binding obligation of such Loan Party, enforceable in accordance with its terms;

(b) No Default or Event of Default shall have occurred and be continuing; and

(c) The representations and warranties made by any Loan Party in and pursuant to the Loan Documents are true and correct in all material respects, after giving effect to this Amendment,

on and as of the Amendment Effective Date as if made on and as of the Amendment Effective Date, except to the extent such representations and warranties expressly relate to an earlier date, in which case such representations and warranties shall have been true and correct in all material respects as of such earlier date.

2. Payment of Expenses. The Parent Borrower agrees to pay and reimburse the Administrative Agent for all of its reasonable out-of-pocket costs and expenses incurred in connection with this Amendment, including without limitation, the reasonable fees and disbursement of one primary counsel to the Administrative Agent (and if necessary or, in the reasonable judgment of the Administrative Agent, advisable, one local counsel in each relevant jurisdiction (which, for the avoidance of doubt, may include Canada)).

3. No Other Modifications; Confirmation. Except as expressly modified hereby, the provisions of the Credit Agreement are and shall remain in full force and effect. Nothing herein shall be deemed to entitle the Borrowers to a consent to, or a waiver, amendment, modification or other change of, any of the terms, conditions, obligations, covenants or agreements contained in the Credit Agreement or any Loan Document in similar or different circumstances.

4. Effect of Amendment. On and after the Amendment Effective Date, each reference in the Credit Agreement to “this Agreement”, “hereunder”, “hereof”, “herein”, or words of like import, and each reference to the Credit Agreement in any other Loan Document shall be deemed a reference to the Credit Agreement as amended hereby. This Amendment shall constitute a “Loan Document” for all purposes of the Credit Agreement and the other Loan Documents.

5. Governing Law; Counterparts.

(a) This Amendment and the rights and obligations of the parties hereto shall be governed by, and construed and interpreted in accordance with, the laws of the State of New York.

(b) This Amendment may be executed by one or more of the parties to this Amendment on any number of separate counterparts, and all of said counterparts taken together shall be deemed to constitute one and the same instrument. Delivery of an executed signature page of this Amendment by facsimile transmission shall be effective as delivery of a manually executed counterpart hereof.

2

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed and delivered by their respective proper and duly authorized officers as of the day and year first above written.

[Lender Signature Pages Provided Separately]

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

IN WITNESS WHEREOF, the undersigned Borrowers have caused this Amendment to be executed and delivered by their duly authorized officers as of the date first above written and the Subsidiary Guarantors hereby consent and agree to this Amendment as of the date hereof and reaffirm their obligations under the Loan Documents to which they are party.

[Loan Parties Pages Provided Separately]

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT

SIGNATURE PAGE – FIRST AMENDMENT TO DOMTAR CREDIT AGREEMENT