HF Sinclair : 2021 Proxy Statement

2021

NOTICE OF ANNUAL MEETING

AND PROXY STATEMENT

Wednesday, May 12, 2021, 8:30 a.m. Central Daylight Time

http://www.virtualshareholdermeeting.com/HFC2021

Dear Fellow Stockholders,

On behalf of the Board, I am pleased to invite you to HollyFrontier's 2021 Annual Stockholders' Meeting, which will be held on Wednesday, May 12, 2021 at 8:30 a.m., Central Daylight Time. Due to the public health impact of the coronavirus (COVID-19) and to support the health and well-being of our stockholders, employees and their families, the Annual Meeting will be held in a virtual meeting format only, via webcast atwww.virtualshareholdermeeting.com/HFC2021.

2020 was an unprecedented year for HollyFrontier. In the face of extraordinary challenges, even as the COVID-19 pandemic and reduced global economic activity affected our businesses and our daily lives, HollyFrontier persevered and took important steps to strengthen our business and extend our long record of value creation. Below are highlights of changes in our leadership, business, governance and director and executive pay in the past year.

Board Changes

In 2020, we were excited to add Manuel (Manny) J. Fernandez to our Board. With more than 36 years of experience at KPMG LLP advising public and private companies across a variety of industries, Mr. Fernandez brings to the Board extensive financial and management experience as well as financial reporting expertise. During his career at KPMG, he also served as National Managing Partner for Talent Acquisition, member of the National Inclusion and Diversity Board and as Co-Chair of the National Hispanic/Latino employee resource group. Having emigrated from Cuba at the age of eight, Mr. Fernandez has a passion for advancing inclusion and diversity, and was recognized for his leadership and dedication to advancing the careers of Latino professionals by The Association of Latino Professionals for America with the Lifetime Achievement Award.

In accordance with our director retirement policy, Douglas Bech will not stand for re-election at the 2021 Annual Meeting. Mr. Bech has served as a director HollyFrontier since the merger of Frontier Oil Corporation and Holly Corporation in July 2011. On behalf of myself, the Board and our employees, I thank Doug for his service and commitment to HollyFrontier.

Strengthening our Executive Leadership Team

This year also marked my return as Chief Executive Officer and President in January 2020. As part of the broader leadership transition, in June 2020, we welcomed Tim Go as Executive Vice President and Chief Operating Officer, and Bruce Lerner as President, HollyFrontier Lubricants and Specialties. Both Tim and Bruce lead key segments of our business, and their leadership, combined with that of the rest of the executive leadership team, will help to advance our business strategies as we continue to build for the future.

Investment in Renewables

In 2020, we continued to advance our renewables strategy to diversify our business, meet the growing demand for lower carbon fuels and position HollyFrontier for sustainable, long-term success. In June 2020, we announced the conversion of our Cheyenne refinery from a traditional petroleum fuels refinery to a renewable diesel facility and the construction of a feedstock pre-treatment unit in Artesia, New Mexico. These renewable investments, combined with our previously announced construction of a renewal diesel unit at our Artesia refinery in November 2019, represent an investment of between $650-$750 million.

Governance

We continue to maintain strong corporate governance practices that promote long-term stockholder value, including a separate independent Chairman of the Board and Chief Executive Officer, annual director elections, no dual class capitalization or 'poison pill', and a majority voting standard for the election of directors in an uncontested election with a director resignation policy. Our Board's Nominating, Governance and Social Responsibility Committee regularly considers and evaluates corporate governance developments and recommends appropriate changes to the Board to maintain its commitment to strong corporate governance. For example, in December 2020 our Board adopted proxy access with market terms (3% for 3 years, up to the greater of two individuals or 20% of the Board). Other highlights of our governance practices are discussed in this proxy statement.

Human Capital

Our Board and its committees provide oversight on our strategies and policies related to human capital management. Our Compensation Committee is responsible for periodically reviewing HollyFrontier's strategies and policies regarding the promotion of employee diversity, equity and inclusion, talent and performance management, pay equity and employee engagement, as well as our executive succession planning.

Our leadership is committed to attracting, retaining and developing a highly engaged, high-performing, diverse workforce and cultivating an inclusive workplace where all employees feel valued and have a sense of belonging. We have introduced diversity awareness programs focused on increasing the number of underrepresented persons in engineering roles in our refineries and corporate office. HollyFrontier is proud of its increased diversity, from our boardroom to the field, and we are dedicated to continuous improvement on this front.

Director and Executive Pay

We understand that director and executive pay should reflect the current circumstances in which we find HollyFrontier. Therefore, in light of economic conditions and our expense reduction efforts, the Board approved a 10% reduction in all Board and committee cash retainers for the second half of 2020 that will continue for 2021.

Additionally, it was important that I too adjust to our current environment. In conjunction with the Board, we determined that my base salary would be reduced by 10% for the second half of 2020 and my 2020 annual bonus would be reduced by 15%. For 2021, my base salary did not increase. These changes in compensation were made to better align our compensation plans with shareholder returns and to reinforce our objective of paying for performance.

Looking Ahead

In 2021, our focus remains on generating high returns while operating safely and efficiently, further improving refinery reliability, progressing our transition into renewables, enhancing our environmental and sustainability performance and reporting, and working to allocate capital in ways that reflect our stockholders' best interests.

On behalf of our Board and our employees, thank you for your trust and investment in HollyFrontier.

Michael C. Jennings

Chief Executive Officer and President

March 25, 2021

NOTICE OF 2021 ANNUAL MEETING

AND PROXY STATEMENT

Dear Stockholder:

You are invited to attend the Annual Meeting of stockholders of HollyFrontier Corporation (the "Company"). The 2021 Annual Stockholders' Meeting ("Annual Meeting") will be held in a virtual meeting format only, via live audio webcast as shown below.

Items of Business

• • Election of 10 directors to hold office until the 2022 annual meeting of stockholders

• • Approval, on an advisory basis, of the compensation of the Company's named executive officers

• • Ratification of the appointment of Ernst & Young LLP as the Company's independent registered public accounting firm for the 2021 fiscal year

• • Consideration of a stockholder proposal for simple majority vote, if properly presented at the Annual Meeting

Who Can Vote

Stockholders of record at the close of business on March 15, 2021 are entitled to receive notice of, and vote at, the Annual Meeting.

Information about the meeting is presented in the following proxy statement. The proxy statement and the form of proxy are being first made available to stockholders on or about March 25, 2021. Please read the enclosed information and our 2020 Annual Report carefully before voting your proxy.

Due to the public health impact of the coronavirus (COVID-19) and to support the health and well-being of our stockholders, employees and their families, the Annual Meeting will be held in a virtual meeting format only, via webcast atwww.virtualshareholdermeeting.com/HFC2021. You will not be able to attend the Annual Meeting physically in person. You will be able to attend and listen to the Annual Meeting online, submit questions and vote your shares electronically during the virtual Annual Meeting. As always, we encourage you to vote your shares prior to the virtual Annual Meeting. In order to attend and vote or submit questions at the Annual Meeting, please follow the instructions in the section titled "General Information-Additional Information About the Virtual Annual Meeting" on page 79.

To participate in the virtual Annual Meeting, you will need the 16-digit control number included on your proxy card, voting instruction form or notice of internet availability. The virtual Annual Meeting will begin promptly at 8:30 a.m., Central Daylight Time, on May 12, 2021. We encourage you to access the virtual Annual Meeting prior to the start time. Online access and check-in will begin at 8:15 a.m., Central Daylight Time. Participants should allow plenty of time to log in and to make sure that they can hear streaming audio prior to the start of the virtual Annual Meeting.