"Yep. it sounds daunting now that over 150,000 Americans are dead because of it. I was one of the lucky ones. Mild symptoms. I count my blessings and urge you to keep wearing the damn mask, keep washing your hands, and stay socially distant," he wrote.
In a video accompanying the post, the former Malcolm in the Middle star, 64, shared his experience donating his own plasma – which now contains coronavirus antibodies – after he'd recovered from the virus.
"I wanted to announce that I had Covid-19 a little while ago. Very lucky, mild symptoms," he told fans.
Cranston is the latest in a long list of celebs to speak out about being diagnosed with coronavirus: Earlier this month it was revealed that actor Mel Gibson was hit with coronavirus in April and spent a week in hospital.
Tom Hanks and wife Rita Wilson were two of the earliest A-list patients, both coming down with COVID-19 during an Australian visit in March.
Broadway actor Nick Cordero's brutal coronavirus battle came to an end this month after more than three months in hospital: After losing a leg, being fitted with a pacemaker and suffering a lung infection, he sadly died at the age of 41.
And Pitch Perfect star Anna Camp revealed this week that she's been diagnosed with coronavirus, despite being very careful: "One time, when the world was starting to open up, I decided to forgo wearing my mask in public. One. Time. And I ended up getting it," she wrote.