Sources close to the couple confirmed the news to Us Weekly two months after it was revealed that Simpson cancelled her original plan to wed in Italy, deciding it would be "too much" to asks guests to travel to Europe.
The 33-year-old designer will reportedly tie the knot to Johnson in Santa Barbara, California. Insiders claim Simpson won't be wearing white for the ceremony, but is having "something unique made" instead.
"We are very close to sending out our invites," Simpson said at the White House Correspondents' Dinner in early May. "I've been very picky on how I want everything to look and feel. Eric's family alone is almost 90 people, so it'll definitely be a big event."
The couple -- who has two children together, daughter Maxwell, 2, and son Ace, 10 months -- became engaged in November 2010.