The 43-year-old South African previously won the Open warm-up event in 2000 and 2003.
"Playing the Aberdeen Asset Management Scottish Open is not only the perfect preparation for The Open, it's also a tremendous tournament in its own right," Els said in a European Tour news release on Tuesday.
"I have very fond memories of my two wins in the Scottish Open and if I can win it a third time next week it would be the perfect platform for my defence of The Open."
World number six Phil Mickelson will also compete at the Castle Stuart course in Inverness from July 11-14.
This year's Open will also be held in Scotland, at Muirfield the following week.
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