X0508 4 2023-09-06 0 0001492426 Horizon Therapeutics Public Ltd Co HZNP 0001230482 SHERMAN JEFFREY W C/O HORIZON THERAPEUTICS PLC, 70 ST. STEPHEN?S GREEN DUBLIN L2 D02 E2X4 IRELAND 0 1 0 0 EVP and Chief Medical Officer 0 Ordinary Shares 2023-09-06 4 G 0 2165 0.00 D 80944 I See Footnote Ordinary Shares 105808 I See Footnote Ordinary Shares 45352 I By Spouse Ordinary Shares 2655 D The shares are held in the Jeffrey W. Sherman Living Trust. 21,378 ordinary shares held indirectly by the reporting person were inadvertently reported on a prior Form 4 as sold on December 12, 2022 by the Jeffrey W. Sherman 2020 Gift Trust. Instead, the ordinary shares were sold by the reporting person's spouse. The reporting person's holdings on this Form 4 have been adjusted accordingly. The shares are held in the name of the Jeffrey W. Sherman 2020 Gift Trust, of which the reporting person's spouse is the Trustee. Includes 279 ordinary shares of the Issuer acquired by the reporting person on June 1, 2023 pursuant to an employee stock purchase program. /s/ Patrick McIlvenny, Attorney-in-Fact 2023-09-07