Other features will work on rival Android handsets but not iPhone.
These include "advanced" sleep and workout tracking, with things like running and walking detected automatically.
And centre of it all is AI, which is used to crunch all the data it's tracked on your health and movements to generate a so-called energy score with tailored tips to boost your wellness.
Apple v Android: Inside the rivalry
Samsung Galaxy Ring, £399 at Samsung
There's also a heart rate checker, as well as cycle tracking for women which can predict the user's menstrual cycle based on overnight skin temperature.
The / $399 - more expensive than most of Samsung's new smartwatches.
Despite the premium price tag, there's no subscription to access any features or your data, unlike market leader Oura's latest .
"The Galaxy Ring is an interesting bet by Samsung," said Ben Wood, Chief Analyst at CCS Insight.
"It’s a device category that fits well with growing consumer interest in tracking health metrics and it is complementary with Samsung’s current smartwatch sales, particularly when monitoring sleep.
Samsung Galaxy Ring: Key facts
Available in nine sizes
Three colours: black, gold and silver
Works with Android smartphones and not iPhone
Titanium grade 5
IP68 rating - protected from water and dust
Battery lasts up to seven days off a single charge
No subscription to access data required
Costs £399
"Only a small proportion of consumers wear their smartwatches in bed which means a huge chunk of data is not captured, not just around sleep, but also heart health, body temperature and more.
"It is also encouraging to see the growing focus on women’s health, a trend that other smart ring makers are embracing."
The smart ring uses scratch resistance titanium and comes in three colours: black, gold and silver.
It'll be available in nine sizes too, alongside a wireless charging case.
The Samsung Galaxy Ring goes on sale from July 24.
Samsung Galaxy Ring, £399 at Samsung
SMARTWATCHES LIVE ON
However, the move doesn't signal the end for Samsung's smartwatches.
The firm has announced new Galaxy Watch devices too, including an Ultra model.
Expert Ben, added: "The new Samsung Galaxy Watch Ultra will doubtless provoke a flurry of discussion regarding its similarity to the design and naming of Apple’s Watch Ultra.
"However, it is a logical next step for Samsung.
"It has correctly identified that the Apple Watch Ultra has been a strong margin driver and the is designed to appeal to a similar demographic, be that aspiring athletes, those seeking a fashion statement, or simply those who want the best specification and battery on their smartwatch."