Exhibit 5.1

Our ref             RDS/604835-000001/21251158v2

The9 Limited

17 Floor, No. 130 Wu Song Road

Hong Kou District, Shanghai 201203

People’s Republic of China

17 November 2021

Dear Sir or Madam

The9 Limited

We have acted as counsel as to Cayman Islands law to The9 Limited (the "Company") in connection with the Company’s automatic shelf registration statement on Form F-3 (File No. 333-254878), filed on 30 March 2021 with the Securities and Exchange Commission under the U.S. Securities Act of 1933, as amended to date, including all amendments or supplements thereto (the "Registration Statement"), and the prospectus supplement (to the prospectus dated 30 March 2021) dated 17 November 2021 (the "Prospectus Supplement") relating to the offering by the Company of 416,705 American Depositary Shares (the "Offered ADSs"), representing 12,501,150 Class A ordinary shares of the Company, par value US$0.01 per share (the "Shares"), to be issued to the Sellers (as defined in the Prospectus Supplement) pursuant to and in accordance with the terms of the SPAs (as defined in the Prospectus Supplement).

We are furnishing this opinion as Exhibits 5.1 and 23.1 to the Registration Statement.

1 Documents Reviewed

For the purposes of this opinion, we have reviewed only originals, copies or final drafts of the following documents and such other documents as we have deemed necessary in order to render the opinions below:

1.1 The certificate of incorporation of the Company dated 22 December 1999 and the certificate of incorporation on change of name of the Company dated 10 February 2004 issued by the Registrar of Companies in the Cayman Islands.

1.2 The second amended and restated memorandum and articles of association of the Company as adopted by a special resolution passed on 6 May 2019 (the "Memorandum and Articles").

1.3 The written resolutions of the directors of the Company dated 9 April 2021 (the "Directors' Resolutions").

1.4 A certificate from a director of the Company, a copy of which is attached hereto (the "Director's Certificate").

1.5 A certificate of good standing dated 5 November 2021 issued by the Registrar of Companies in the Cayman Islands (the "Certificate of Good Standing").

1.6 The Registration Statement.

1.7 The Prospectus Supplement.

2 Assumptions

The following opinions are given only as to, and based on, circumstances and matters of fact existing and known to us on the date of this opinion letter. These opinions only relate to the laws of the Cayman Islands which are in force on the date of this opinion letter. In giving these opinions we have relied (without further verification) upon the completeness and accuracy, as of the date of this opinion letter, of the Director's Certificate and the Certificate of Good Standing. We have also relied upon the following assumptions, which we have not independently verified:

2.1 Copies of documents, conformed copies or drafts of documents provided to us are true and complete copies of, or in the final forms of, the originals.

2.2 All signatures, initials and seals are genuine.

2.3 There is nothing under any law (other than the laws of the Cayman Islands) which would or might affect the opinions set out below. Specifically, we have made no independent investigation of the laws of the State of New York.

2.4 There is nothing contained in the minute book or corporate records of the Company (which we have not inspected) which would or might affect the opinions set out below.

3 Opinion

Based upon the foregoing and subject to the qualifications set out below and having regard to such legal considerations as we deem relevant, we are of the opinion that:

3.1 The Company has been duly incorporated as an exempted company with limited liability and is validly existing and in good standing with the Registrar of Companies under the laws of the Cayman Islands.

3.2 The authorised share capital of the Company is US$50,000,000 divided into (i) 4,300,000,000 Class A Ordinary Shares of a par value of US$0.01 each, (ii) 600,000,000 Class B Ordinary Shares of a par value of US$0.01 each and (iii) 100,000,000 shares of a par value of US$0.01 each of such class or classes as the board of directors of the Company may determine in accordance with the Memorandum and Articles.

3.3 The issue and allotment of the Shares have been duly authorised and when allotted, issued and paid for as contemplated in the Registration Statement and the Prospectus Supplement, the Shares will be legally issued and allotted, fully paid and non-assessable. As a matter of Cayman Islands law, a share is only issued when it has been entered in the register of members (shareholders).

4 Qualifications

The opinions expressed above are subject to the following qualifications:

4.1 To maintain the Company in good standing with the Registrar of Companies under the laws of the Cayman Islands, annual filing fees must be paid and returns made to the Registrar of Companies within the time frame prescribed by law.

4.2 Under the Companies Act (As Revised) of the Cayman Islands, the register of members of a Cayman Islands company is by statute regarded as prima facie evidence of any matters which the Companies Act (As Revised) directs or authorises to be inserted therein. A third party interest in the shares in question would not appear. An entry in the register of members may yield to a court order for rectification (for example, in the event of fraud or manifest error).

4.3 The phrase "non-assessable" means, with respect to the Shares in the Company, that a shareholder shall not, solely by virtue of its status as a shareholder, be liable for additional assessments or calls on the Shares by the Company or its creditors (except in exceptional circumstances, such as involving fraud, the establishment of an agency relationship or an illegal or improper purpose or other circumstances in which a court may be prepared to pierce or lift the corporate veil).

Except as specifically stated herein, we express no view as to the commercial terms of the transactions referred to in or contemplated by the Registration Statement or the Prospectus Supplement, or the offering of the Offered ADSs, or the issue, allotment or deposit of the Shares, or whether such terms represent the intentions of the parties, and we make no comment with regard to warranties or representations that may be made by the Company.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to our name under the headings "Enforceability of Civil Liabilities" and "Legal Matters" and elsewhere in the prospectus included in the Registration Statement. In giving such consent, we do not thereby admit that we come within the category of persons whose consent is required under Section 7 of the U.S. Securities Act of 1933, as amended, or the Rules and Regulations of the Commission thereunder.

Yours faithfully

Maples and Calder (Hong Kong) LLP