There is no option to buy and no loan fee, but the Spanish club will cover the striker's wages.
The Frenchman, 26, has been targeted by Sevilla for a number of months.
Upon completing the deal Sevilla tweeted they had signed "a luxury reinforcement" and "a very special gift" for fans on what was the club's 132nd anniversary.
It is thought Martial has indicated a willingness to take a pay cut to allow the deal to go through.
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