The 34-year-old designer and 35-year-old retired NFL tight end celebrated the anniversary by sharing a number of photos together on Instagram. The couple married in July 2014, and have two children, daughter Maxwell and son Ace.
"The sexiest day of my life was 5yrs ago when Johnson came into my home #MAY21," Simpson captioned one of the snapshots. "We are awesome #MAY21 #5yrs."
Simpson was previously wed to 98 Degrees singer Nick Lachey from 2002 to 2006. Lachey went on to marry Vanessa Minnillo in 2011, and subsequently told Jenny McCarthy he is happy he and Simpson didn't have children. He and Minnillo share son Camden and daughter Brooklyn.
Simpson last released Do You Know in 2008, and announced she has her eighth record in the works in March. The singer continues to design shoes and handbags for her Jessica Simpson Collection, and also oversees fragrance and home decor lines.