The tennis coach joins Frankie Bridge from pop act The Saturdays, who last week announced she too will be taking part in the show.
Ms Murray said: "I'm a huge Strictly Come Dancing fan but a total armchair dancer.
"It's going to be a big challenge for me and for whoever has to dance with me but I absolutely can't wait to get started."
She was said to be in talks with show bosses during the summer as Andy tried to defend his Wimbledon title but crashed out to Grigor Dimitrov.
Murray, 54, qualified as a tennis coach aged 17 and become the eighth-best woman player in the UK.
She has previously posted comments about Strictly on Twitter.