The 'Adore You' hitmaker has designed the piece of clothing, which he is selling on his official store for £21 / $26 to support the response to COVID-19.
The t-shirts are white and have the phrase, "Stay Home. Stay Safe. Protect Each Other," printed on them, with all of the profits going towards the World Health Organisation's COVID-19 Solidarity Response Fund.
The description reads: "This tee is in support of the WHO efforts to fight COVID-19. 100% of profits to be donated to the COVID-19 Solidarity Response Fund for the World Health Organisation, powered by the UN Foundation."
The t-shirts - which have Harry's trademark "treat people with kindness" phrase printed on the back - are expected to ship in four to six weeks time.
It comes after Harry joked he doesn't have a "real job" so he is doing "whatever" during isolation as he is currently stuck in California with his friends.
Giving an update on his self-isolation, he said recently: "I'm with people who have real jobs, so they're working ... which leaves me with not a real job, doing kind of whatever. I'm reading a lot, doing a lot of writing, trying to exercise, trying to be outside. And then we kind of all get together in the evening and watch a film."
Harry previously revealed he is stranded in the US because the current coronavirus pandemic - which has halted most flights around the world - meant he couldn't get back to the UK before the lockdown started.
Speaking earlier this week, he said: "I'm actually in California, I got stuck. I was supposed to be coming home then it all got a bit sketchy with the flights."
And it's not just his travel plans that COVID-19 has disrupted, as the 26-year-old singer has also been forced to reschedule his UK and Europe tour, which was meant to kick off next month, until 2021 due to the ongoing global health crisis.
He explained: "It's obviously disappointing but it's not even close to being the most important thing at all right now.
"But it's okay, I think that everybody understands it's not really like there's anything you can do about it and I think the most important thing is to keep everyone safe. I'm really looking forward to it when it comes around. We'll be very ready by then."
