X0306 4 2021-09-23 0001743907 Sun Country Airlines Holdings, Inc. SNCY 0001850489 Whitney Grant C/O SUN COUNTRY AIRLINES HOLDINGS, INC. MINNEAPOLIS MN 55450 1 Chief Revenue Officer & EVP Common Stock, par value $0.01 per share 2021-09-23 4 M 0 983 5.30 A 2320 D Common Stock, par value $0.01 per share 2021-09-23 4 S 0 983 35.5058 D 1337 D Employee Stock Option (Right to Buy) 5.30 2021-09-23 4 M 0 983 0 D 2029-07-31 Common Stock 983 98455 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $35.50 to $35.52, inclusive. The reporting person undertakes to provide to Sun Country Airlines Holdings, Inc. ("Sun Country"), any security holder of Sun Country, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2) to this Form 4. Vest in four annual installments, subject to continued service, beginning May 20, 2020. /s/ Eric Levenhagen, as attorney-in-fact for Grant Whitney 2021-09-24