The pair have been dating for five years and met in a hotel bar in Tokyo.
The happy news comes shortly after the sudden death of Jenson's father, John Button, who died in January aged 70.
The McLaren racing team congratulated the pair on Twitter: "Huge congrats to @JensonButton and @jessybondgirl on their engagement!"
Michibata was pictured in the paddock during day three of Formula One winter testing at the Bahrain International Circuit and was wearing an impressive silver band.
LBC