The crew of the Portsmouth-based carrier can contact friends and family by posting updates and pictures from sea.
Twitter users can also message the crew back.
Messages include information about choir practice and a chemical training exercise, complete with images of the crew in chemical suits and respirators.
A recent post says: “Just had our brief for our final training war tomorrow. We are all living up to our motto – ‘Zeal does not rest’.”
HMS Ark Royal’s commanding officer, Captain John Clink, said he was keen to keep up with the latest technology.
“For hundreds of years the Royal Navy has been at the forefront of technology – particularly communications between ship and shore,” he said.
“So it’s no surprise to me that we are embracing all available media, especially the internet, to keep the public up to date with our operations.
“Twitter gives Ark Royal an immediate, up-to-the-minute link into her followers, many of whom will be friends and family.”
The launch of Twitter on Ark Royal comes a month after the navy gave personal games consoles to sailors for engineering and maths challenges.