Graphic Packaging Holding (GPK) 10-Q 2023 Q3 Quarterly report

Exhibit 32.1

CERTIFICATION

Pursuant to 18 United States Code Section 1350,

As adopted pursuant to Section 906 of the

Sarbanes-Oxley Act of 2002

The undersigned hereby certifies that, to my knowledge, the Quarterly Report on Form 10-Q for the period ended September 30, 2023 of Graphic Packaging Holding Company (the “Company”) filed with the Securities and Exchange Commission on the date hereof fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that the information contained in such report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Michael P. Doss

Name: Michael P. Doss,
Title: President and Chief Executive Officer

October 31, 2023