The singer and rapper showed her surprise about the radio DJ being "sacked" on her official Twitter page.
She said: "Ur kidding right? Wtf?", before sending him the message: "dm ur nmbr. U need to come to the States! Ur a f**king gold mine. No one in their right mind fired u."
The star later added: "Noooooooooooooo Tim Westwood is such a big part of my UK experience!!!!! He's a f**king superstar!!!! Best interviews hands down!!!! Wtf?!?!"
Westwood will continue to present his Saturday night show simulcast on Radio 1 and Radio 1Xtra, as well as fronting a new Sunday evening programme between 7pm and 9pm.
Watch a clip from Tim Westwood's famous freestyle sessions below: