Exhibit 5.1

[CONYERS DILL & PEARMAN LETTERHEAD]

11 September 2013

Matter No. 877864

Doc Ref: AC/al/3321222v3

Montage Technology Group Limited

Room A1601, Technology Building

900 Yi Shan Road

Xuhui District

Shanghai, 200233

People’s Republic of China

Dear Sirs,

Re: Montage Technology Group Limited (the “Company”)

We have acted as special legal counsel in the Cayman Islands to the Company in connection with a registration statement on form S-1 initially filed with the U.S. Securities and Exchange Commission (the “Commission”) on 21 August 2013 (the “Registration Statement”, which term does not include any other document or agreement whether or not specifically referred to therein or attached as an exhibit or schedule thereto) relating to the registration under the U.S. Securities Act of 1933, as amended, (the “Securities Act”) of ordinary shares, par value US$0.0125 each (the “Ordinary Shares”) of the Company.

For the purposes of giving this opinion, we have examined a copy of the Registration Statement. We have also reviewed the amended and restated memorandum of association and the articles of association of the Company adopted on 17 September 2009, the amended and restated memorandum of association and articles of association conditionally adopted by the Company on 13 August 2013 and to become effective immediately prior to the consummation of the offering of Ordinary Shares, copies of resolutions of the board of directors of the Company dated 5 April 2013, minutes of the meeting of the board of directors of the Company held on 13 August 2013, minutes of an extraordinary general meeting of the Company held on 13 August 2013 and minutes of the extraordinary general meeting of the Company held on 6 September 2013 (together,

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the “Minutes”), a copy of a certificate of good standing dated 20 August 2013 (the “Certificate Date”) issued by the Cayman Islands Registrar of Companies and such other documents and made such enquiries as to questions of law as we have deemed necessary in order to render the opinion set forth below.

We have assumed (a) the genuineness and authenticity of all signatures and the conformity to the originals of all copies (whether or not certified) examined by us and the authenticity and completeness of the originals from which such copies were taken, (b) that where a document has been examined by us in draft form, it will be or has been executed and/or filed in the form of that draft, and where a number of drafts of a document have been examined by us all changes thereto have been marked or otherwise drawn to our attention, (c) the accuracy and completeness of all factual representations made in the Registration Statement and other documents reviewed by us, (d) that the resolutions contained in the Minutes were passed at one or more duly convened, constituted and quorate meetings, or by unanimous written resolutions, remain in full force and effect and have not been rescinded or amended, (e) that there is no provision of the law of any jurisdiction, other than the Cayman Islands, which would have any implication in relation to the opinions expressed herein, (f) that upon issue of any shares to be sold by the Company the Company will receive consideration for the full issue price thereof which shall be equal to at least the par value thereof, (g) the validity and binding effect under the laws of the United States of America of the Registration Statement and that the Registration Statement will be duly filed with the Commission, and (h) that the Prospectus contained in the Registration Statement, when declared effective by the Commission will be in substantially the same form as that examined by us for purposes of this opinion.

We have made no investigation of and express no opinion in relation to the laws of any jurisdiction other than the Cayman Islands. This opinion is to be governed by and construed in accordance with the laws of the Cayman Islands and is limited to and is given on the basis of the current law and practice in the Cayman Islands. This opinion is issued solely for the purposes of the filing of the Registration Statement and the offering of the Ordinary Shares by the Company and is not to be relied upon in respect of any other matter.

On the basis of and subject to the foregoing, we are of the opinion that:

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We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the references to our firm under the captions “Enforceability of Civil Liabilities”, “Taxation – Cayman Islands Taxation” and “Legal Matters” in the prospectus forming a part of the Registration Statement. In giving this consent, we do not hereby admit that we are experts within the meaning of Section 11 of the Securities Act or that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the Rules and Regulations of the Commission promulgated thereunder.

Yours faithfully,

/s/ Conyers Dill & Pearman

Conyers Dill & Pearman (Cayman) Limited

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