She was introduced by her ex-husband David Arquette who tweeted "Oh my goodness - It's a miracle. Welcome to twitter Courteney! Don't let the haters discourage you. There's a lot of love 4u".
Courtney seems to be loving the attention, already having 47,645 followers in just 20 hours, she tweeted "WOW! this is fun, but i think my computer is starting to smoke."
The brunette also seems keen to promote her TV series 'Couger Town' making its poster her background and the title her biography.
She has already found time to follow 36 people and tweet two photographs.
Welcome to Twitter Courtney, we have a few small tips for you…
1. DON'T get into any Twitter rows…they never end well *cough* Wayne Rooney/Frankie Cocozza *cough*
2. DON'T brag, we hate braggers, just look at Kanye West
3. DON'T tweet whilst you're drunk. Just don't.
4. DO respond to your fans & let us know what you're up to (in a non look-at-me-I'm-amazing way)
5. DON'T give us too much information (see our TMI feature here)
We reckon Courtney will be a wonderful tweeter, she even took time to thank fans "Thank you all for making me feel so welcome today!!".