Murray the British number one reached the Wimbledon final after beating Jo-Wilfried Tsonga in four sets on centre court.
The Prime Minister said:
It is great news that we have our first home-grown men’s finalist at Wimbledon for over 70 years, especially in this exciting Olympics year when the eyes of the world are on the UK.
I’ll be watching the final on Sunday and like the rest of the country, will be getting right behind Andy Murray - I wish him the best of luck.
Downing Street will fly the Saltire alongside the Union Flag on Sunday in support of Andy Murray in the final.