Page 1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K × ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR □ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period to * ** Commission file number : 000-28508 AVADEL PHARMACEUTICALS PLC ( Exact name of registrant as specified in its charter ) Ireland 98-1341933 State or other jurisdiction of incorporation or organization ( I.R.S. Employer Identification No. ) 10 Earlsfort Terrace Dublin 2 , Ireland D02 T380 ( Address of principal executive offices ) Registrant's telephone number , including area code : + 011-1-485-1200 Securities registered pursuant to Section 12 ( b ) of the Act : Not Applicable ( Zip Code ) Title of each class American Depositary Shares * Ordinary Shares , nominal value $ 0.01 per share ** Trading Symbol ( s ) AVDL AVDL Name of exchange on which registered The Nasdaq Global Market The Nasdaq Global Market American Depositary Shares may be evidenced by American Depository Receipts . Each American Depositary Share represents one ( 1 ) Ordinary Share . Not for trading , but only in connection with the listing of American Depositary Shares . on The Nasdaq Global Market . Securities registered pursuant to Section 12 ( g ) of the Act : None Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes ☐ No ☑ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes ☐ No ☑ Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes ý No Indicate by check mark whether the registrant has submitted electronically , every Interactive Data File required to be submitted and pursuant to Rule 405 of Regulation S - T ( $ 232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No □ Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company or an emerging growth company . See the definitions of “ large accelerated filer ” , “ accelerated filer ” , “ smaller reporting company ” , and “ emerging growth company " in Rule 12b - 2 of the Exchange Act . Large accelerated filer Non - accelerated filer Accelerated filer ý Smaller reporting company □ Emerging growth company If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . ý Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes □ No ☑ The aggregate market value of voting stock held by non - affiliates of the registrant as of the last business day of the registrant's most recently completed second fiscal quarter was $ 466,741,289 based on the closing sale price of the registrant's American Depositary Shares as reported by the Nasdaq Global Market on June 30 , 2020. Such market value excludes 364,026 ordinary shares , $ 0.01 per share nominal value , held by each officer and director and by shareholders that the registrant concluded were affiliates of