Jamaican sprint star Shelly-Ann Fraser-Pryce will also run in the 200m when she defends her Olympic 100m title in Tokyo next year.
It is set to be the final Olympics for Fraser-Pryce, who will be 33 on Friday.
"I will be doubling up definitely," she was quoted as saying in Kingston by website Inside the Games.
"Last year [season] I really wanted to attempt the double but my coach had other plans so I just worked with that plan. He knows best."
Fraser-Pryce's Olympic best at 200m was a silver medal at London 2012, although she did triumph at that distance in this year's Pan American Games.
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Her main rivals in the 200m in Tokyo will include Britain's Dina Asher-Smith, who is fresh from winning gold at that distance in the recent World Championships in Doha - but took 100m silver behind Fraser-Pryce at the same championships.