Exhibit 5.1

601 Lexington Avenue New York, NY 10022 United States +1 212 446 4800   www.kirkland.com Facsimile: +1 212 446 4900

June 26, 2024

WEBTOON Entertainment Inc.

5700 Wilshire Blvd., Suite 220

Los Angeles, CA 90036

Re: Registration Statement on Form S-8

We are issuing this opinion in our capacity as special legal counsel to WEBTOON Entertainment Inc., a Delaware corporation (the “Company”), in connection with the filing by the Company of a Registration Statement on Form S-8 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Act”), with the Securities and Exchange Commission (the “Commission”) covering the offering of up to 28,365,337 shares (the “Plan Shares”) of common stock, par value $0.0001 per share, of the Company issuable pursuant to (a) the Company’s 2020 Stock Option Plan, (b) the Company’s Amended and Restated 2020 Stock Option Plan, (c) the Company’s Second Amended and Restated 2020 Stock Option Plan, (d) the Company’s Third Amended and Restated 2020 Equity Incentive Plan, and (e) the Company’s 2024 Omnibus Incentive Plan (each, a “Plan” and, together, the “Plans”).

In connection therewith, we have examined originals, or copies certified or otherwise identified to our satisfaction, of such documents, corporate records and other instruments as we have deemed necessary for the purpose of this opinion, including (i) the corporate and organizational documents of the Company, (ii) the Registration Statement and the exhibits thereto, (iii) minutes and records of the corporate proceedings of the Company with respect to the offering of the Plan Shares and (iv) the Plans.

For purposes of this opinion, we have assumed the authenticity of all documents submitted to us as originals, the conformity to the originals of all documents submitted to us as copies and the authenticity of the originals of all documents submitted to us as copies. We have also assumed the legal capacity of all natural persons, the genuineness of the signatures of persons signing all documents in connection with which this opinion is rendered, the authority of such persons signing on behalf of the parties thereto (other than the Company), and the due authorization, execution and delivery of all documents by the parties thereto (other than the Company). As to any facts material to the opinions expressed herein which we have not independently established or verified, we have relied upon statements and representations of officers and other representatives of the Company and others.

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WEBTOON Entertainment Inc.

June 26, 2024

Page 2

Based upon and subject to the assumptions, qualifications and limitations identified in this opinion, we are of the opinion that the Plan Shares are duly authorized and when the Plan Shares are issued pursuant to and in accordance with the terms and conditions of the applicable Plan and the Company’s Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws, the Plan Shares will be validly issued, fully paid and non-assessable.

Our opinions expressed above are subject to the qualifications that we express no opinion as to the applicability of, compliance with, or effect of any laws except the General Corporation Law of the State of Delaware.

For purposes of rendering our opinions expressed above, we have assumed that (i) the Registration Statement remains effective during the offer and sale of the Plan Shares, and that (ii) at the time of the issuance, sale and delivery of each Plan Share, there will not have occurred any change in law affecting the validity, legally binding character or enforceability of such Plan Share. We have also relied without independent investigation upon, among other things, an assurance from the Company that the number of shares which the Company is authorized to issue in its Amended and Restated Certificate of Incorporation exceeds the number of shares outstanding and the number of shares which the Company is obligated to issue (or had otherwise reserved for issuance) for any purposes other than issuances of the Plan Shares by at least the number of Plan Shares and we have assumed that such condition will remain true at all future times relevant to this opinion.

We do not find it necessary for the purposes of this opinion, and accordingly we do not purport to cover herein, the application of the securities or “Blue Sky” laws of the various states to the issuance and sale of the Plan Shares.

This opinion is limited to the specific issues addressed herein, and no opinion may be inferred or implied beyond that expressly stated herein. This opinion speaks only as of the date hereof, and we assume no obligation to revise or supplement this opinion should the General Corporation Law of the State of Delaware be changed by legislative action, judicial decision or otherwise after the date hereof.

This opinion is furnished to you in connection with the filing of the Registration Statement, and is not to be used, circulated, quoted or otherwise relied upon for any other purposes.

WEBTOON Entertainment Inc.

June 26, 2024

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We hereby consent to the filing of this opinion with the Commission as Exhibit 5.1 to the Registration Statement. In giving this consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission.

Sincerely,

/s/ Kirkland & Ellis LLP

KIRKLAND & ELLIS LLP