Steve Smith will prepare for the Ashes and Australia's likely participation in the World Test Championship final by playing three County Championship games for Sussex.
The prolific batter will face Worcestershire and Leicestershire before coming up against Australia team-mate Marnus Labuschagne in a Division Two match against Glamorgan in May.
Smith, ranked as the second-best Test batter in the world behind Labuschagne, is then expected to feature in the World Test Championship final at The Oval in June – with Australia having all-but qualified.
The former Australia captain will hope a short spell with Sussex ensures he is in great touch by the time the first Ashes Test starts against England at Edgbaston on June 16.
Smith told Sussex's official website: "I am excited about joining Sussex for a few games in May and hopefully making a contribution to a successful season.
"I am particularly looking forward to working with the younger players in the squad and hoping I can provide some guidance to them."
The 33-year-old has previous experience of playing county cricket for Worcestershire.
Smith made a staggering 30th Test century in his last appearance for his country against South Africa at the SCG this month.