The Duchess of Cambridge will present the BBC's Sports Personality of the Year award and the lifetime achievement honour tonight, St. James's Palace said.
Catherine has not been seen in public since leaving the King Edward VII's Hospital in London on December 6.
She received three days of treatment for a condition known as hyperemesis gravidarum, which leaves expectant mothers so ill they cannot keep food or liquids down.
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The 23-year-old dived to his second World Championships 10-metres platform title in Budapest on Saturday.
Heavy rain continues across southern Scotland/northern England and the southwest.
Staff at the hospital treating critically-ill baby Charlie Gard have received "shocking" abuse including death threats over the case.