Exhibit 5.1

A&L Goodbody Suite 33D The Chrysler Building 405 Lexington Avenue New York NY 10174

Tel: +1 212 582 4499 Fax: +1 212 333 5126 email: newyork@algoodbody.com website: www.algoodbody.com

Our ref

01-423368

Your ref

Date

20 September 2017

Nabriva Therapeutics plc
25-28 North Wall Quay
Dublin 1
Ireland

Re: Nabriva Therapeutics plc (the Company)

Dear Sirs

We are acting as Irish counsel to the Company, a public limited company incorporated under the laws of Ireland (registered number 599588), in connection with the issuance by the Company of up to 10,823,529 ordinary shares, par value $0.01 per share (the Shares) pursuant to (i) a registration statement on Form S-3 (File No. 333-219567) filed by the Company, on 28 July 2017, with the U.S. Securities and Exchange Commission (the SEC) under the Securities Act of 1933, as amended (the Securities Act), as amended on 4 August 2017, (the Registration Statement) and the prospectus contained therein (the Base Prospectus) for the registration of, among other things, ordinary shares, par value $0.01 per share, of the Company, which may be issued from time to time on a delayed or continuous basis pursuant to Rule 415 under the Securities Act at an initial aggregate offering price not to exceed $175,000,000; (ii) the preliminary prospectus supplement dated September 18, 2017 (the Preliminary Prospectus Supplement), and (iii) the prospectus supplement, dated September 19, 2017 (the Prospectus Supplement, and together with the Base Prospectus and the Preliminary Prospectus Supplement, the Prospectus) relating to the issuance by the Company of the Shares.

Morgan Stanley & Co. LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated, SunTrust Robinson Humphrey, Inc., Needham & Company, LLC and Wedbush Securities Inc. (the Underwriters) have acted as underwriters to this proposed primary equity offering, as documented in an underwriting agreement between the Company and the Underwriters dated September 19, 2017 (the Underwriting Agreement) (the Underwriting Agreement, together with the Registration Statement and the Prospectus, the Transaction).

In connection with this Opinion, we have examined and relied upon copies of:

· the Registration Statement;

· the Prospectus; and

Dublin Belfast London New York San Francisco Palo Alto

P.M. Law

L.A. Kennedy

K.A. Feeney

G. O’Toole

S. O’Croinin

A.M. Curran

P.M. Murray

M. Coghlan

K. Ryan

R. Lyons

J. Williams

C.E. Gill

S.M. Doggett

M. Sherlock

J.N. Kelly

J.W. Yarr

A. Roberts

N. Ryan

D.R. Francis

E. Hurley

J. Sheehy

A. O’Beirne*

E.M. FitzGerald

B. McDermott

E.P. Conlon

N. O’Sullivan

D.R. Baxter

M. Dale

P. Walker

A. Casey*

G. Stanley

C. Morrissey

M.D. Cole

J. G. Grennan

C. Duffy

E. MacNeill

M.J. Ward

A. McCarthy

R.M. Moore

K. Furlong

B. Hosty

D. Dagostino

C. McLoughlin

G. Conheady*

J. Coman

P.V. Maher

K.P. Allen

A.C. Burke

J.F. Whelan

D. Main

P.T. Fahy

M. O’Brien

E. Keane

C. Carroll

P.D. White

S. O’Riordan

E.A. Roberts

D. Widger

J.B. Somerville

J. Cahir

M. Rasdale

K. Killalea

C. Clarkin

S.E. Carson

V.J. Power

M.P. McKenna

C. Rogers

C. Christle

M.F. Barr

M. Traynor

D. Inverarity

L. Mulleady

R. Grey

P. Diggin

Consultants: J.R. Osborne S.W. Haughey Professor J.C.W. Wylie A.F. Browne M.A. Greene A.V. Fanagan J.A. O’Farrell I.B. Moore

Each of the partners of A&L Goodbody set out above practises as an Irish Law Attorney.

* Resident in U.S.

· copies of such corporate records of the Company as we have deemed necessary as a basis for the opinions hereinafter expressed.

In rendering this Opinion, we have examined, and have assumed the truth and accuracy of the contents of, such documents and certificates of officers of the Company and of public officials as to factual matters and have conducted such searches, as of the date hereof, in public registries in Ireland as we have deemed necessary or appropriate for the purposes of this Opinion but have made no independent investigation regarding such factual matters. In our examination we have assumed the (continued) truth and accuracy of the information contained in such documents, the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as certified or photostatic copies and the authenticity of the originals of such documents.

We have further assumed that:

1. none of the resolutions and authorities of the Board or shareholders of the Company upon which we have relied have been or will be varied, amended or revoked in any respect or have expired and that the Shares will be issued in accordance with such resolutions and authorities; and

2. the absence of fraud on the part of the Company and its respective officers, employees, agents and advisers and that the Company will issue the Shares in good faith, for its legitimate and bona fide business purposes. We have further assumed that: (i) the Company will be fully solvent at the time of and immediately following the issue of any Shares; (ii) no resolution or petition for the appointment of a liquidator or examiner will be passed or presented prior to the issue of any Shares; (iii) no receiver will have been appointed in relation to any of the assets or undertaking of the Company prior to the issue of any Shares and (iv) no composition in satisfaction of debts, scheme of arrangement, or compromise or arrangement with creditors or members (or any class of creditors or members) will be proposed, sanctioned or approved in relation to the Company prior to the issue of the Shares.

Subject to the foregoing and to the within additional qualifications and assumptions, we are of the opinion that the Shares, when issued in accordance with the Underwriting Agreement will be duly authorised, validly issued, fully paid and will not be subject to calls for any additional payments (non-assessable).

In rendering this Opinion we have confined ourselves to matters of Irish law. We express no opinion on any laws other than the laws of Ireland (and the interpretation thereof) in force as at the date hereof. This Opinion speaks only as of its date. We are not under any obligation to update this Opinion from time to time, nor to notify you of any change of law, facts or circumstances referred to or relied upon in the giving of this Opinion.

This Opinion is given solely for the benefit of the addressee of this Opinion and may not be relied upon by any other person without our prior written consent, provided, however, that it may be relied upon by persons entitled to rely on it pursuant to applicable provisions of US federal securities laws.

This Opinion is also strictly confined to the matters expressly stated herein and is not to be read as extending by implication or otherwise to any other matter.

We hereby consent to the filing of this Opinion with the SEC as an exhibit to the Company’s Current Report on Form 8-K filed with the SEC on September 20, 2017 and to the use of our name therein and in the related Prospectus Supplement under the caption “Legal Matters.”

The Opinion is governed by and construed in accordance with the laws of Ireland.

Yours faithfully,

/s/ A&L Goodbody

A&L Goodbody