Exhibit 10.21

VIKING CRUISES LTD

9.125% SENIOR NOTES DUE 2031

FIRST SUPPLEMENTAL INDENTURE

Dated as of February 23, 2024

to

INDENTURE

Dated as of June 30, 2023

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., as Trustee

FIRST SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of February 23, 2024, among Viking Cruises Ltd, an exempted company incorporated with limited liability organized under the laws of Bermuda (the “Company”), the guarantors party thereto (the “Guarantors”) and The Bank of New York Mellon Trust Company, N.A., a national banking association, as trustee under the Indenture hereinafter referred to (in such capacity, the “Trustee”).

RECITALS

WHEREAS, the Company has heretofore executed and delivered to the Trustee an Indenture dated as of June 30, 2023 (the “Indenture”), pursuant to which the Company has issued $720,000,000 aggregate principal amount of its 9.125% Senior Notes due 2031 (the “Notes”), which are guaranteed by the guarantors party to the Indenture;

WHEREAS, Section 9.01(a)(5) of the Indenture provides, among other things, that the Company, the guarantors party thereto and the Trustee may amend or supplement the Indenture without the consent of any Holder of outstanding Notes to conform the text of the Indenture to any provision of the “Description of Notes” section of the Offering Memorandum (as defined in the Indenture) to the extent that such provision in that “Description of Notes” was intended to be a verbatim recitation of a provision of this Indenture, which intent may be evidenced by an Officer’s Certificate to that effect;

WHEREAS, the Company has requested and hereby directs that the Trustee join with the Company and the Guarantors in the execution of this Supplemental Indenture;

WHEREAS, the Company has duly adopted, and delivered to the Trustee, resolutions of its Board of Directors authorizing the execution of and approving this Supplemental Indenture; and

WHEREAS, all conditions necessary to authorize the execution and delivery of this Supplemental Indenture by the Company and to make this Supplemental Indenture valid and binding on the Company have been complied with or have been done or performed.

NOW, THEREFORE, in consideration of the premises and for other good and valuable consideration, the sufficiency and adequacy of which are hereby acknowledged, the parties hereto hereby agree as follows:

ARTICLE I

DEFINITIONS

Section 1.01 Definitions.

All capitalized terms used and not otherwise defined herein shall have the meanings ascribed thereto in the Indenture.

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ARTICLE II

AMENDMENTS

Section 2.01 Amendments to Section 1.01.

In clause (a) of Section 3.07 of the Indenture, the percentage “9.125%” is hereby replaced with the percentage “109.125%”.

ARTICLE III

EFFECT

Section 3.01 Effectiveness.

This Supplemental Indenture shall become effective upon its execution and delivery by the parties hereto.

ARTICLE IV

MISCELLANEOUS

Section 4.01 Governing Law.

THE INTERNAL LAW OF THE STATE OF NEW YORK WILL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE.

Section 4.02 Counterpart Originals.

The parties may sign any number of copies of this Supplemental Indenture. Each signed copy will be an original, but all of them together represent the same agreement. The exchange of copies of this Supplemental Indenture and of signature pages by facsimile or electronic format (i.e., “pdf” or “tif” or any electronic signature complying with the U.S. federal ESIGN Act of 2000) or other electronically imaged transmission shall constitute effective execution and delivery of this Supplemental Indenture as to the parties hereto and may be used in lieu of the original Supplemental Indenture for all purposes. Signatures of the parties hereto transmitted by facsimile or electronic format (i.e., “pdf” or “tif” or any electronic signature complying with the U.S. federal ESIGN Act of 2000) or other electronically imaged transmission shall be deemed to be their original signatures for all purposes. Any certificate and any other document delivered in connection with this Supplemental Indenture may be signed by or on behalf of the signing party by manual, facsimile or electronic format (i.e., “pdf” or “tif” or any electronic signature complying with the U.S. federal ESIGN Act of 2000) or other electronically imaged transmission. The Trustee shall not have a duty to inquire into or investigate the authenticity or authorization of any such electronic signature and shall be entitled to conclusively rely on any such electronic signature without any liability with respect thereto.

Section 4.03 Table of Contents; Headings.

The headings of the Articles and Sections of this Supplemental Indenture have been inserted for convenience of reference only, are not to be considered a part of this Supplemental Indenture and will in no way modify or restrict any of the terms or provisions hereof.

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Section 4.04 Trustee Not Responsible for Recitals.

The statements and recitals contained herein shall be taken as statements and recitals of the Company, and the Trustee does not assume any responsibility for their correctness. The Trustee makes no representations as to, and shall not be responsible in any manner whatsoever for or in respect of, (i) the validity, sufficiency or adequacy of this Supplemental Indenture, (ii) the proper authorization hereby by the Company by action or otherwise, (iii) the due execution hereof by the Company or (iv) the consequences of any amendment herein provided for.

Section 4.05 Adoption, Ratification and Confirmation.

The Indenture, as supplemented and amended by this Supplemental Indenture, is in all respects hereby adopted, ratified and confirmed.

Section 4.06 Enforceability.

The Company hereby represents and warrants that this Supplemental Indenture is its legal, valid and binding obligation, enforceable against it in accordance with its terms.

Section 4.07 Severability.

In case any provision in this Supplemental Indenture is invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions will not in any way be affected or impaired thereby.

[Signature Page Follows]

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IN WITNESS WHEREOF, the parties have caused this Supplemental Indenture to be duly executed as of the date first written above.

[Signature Page to First Supplemental Indenture]

[Signature Page to First Supplemental Indenture]

[Signature Page to First Supplemental Indenture]

[Signature Page to First Supplemental Indenture]

[Signature Page to First Supplemental Indenture]

[Signature Page to First Supplemental Indenture]

[Signature Page to First Supplemental Indenture]

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