Ultra-thin watches make the headlines for plenty of reasons.

The biggest being that they’re engineering feats that simply don’t just come out of the blue, and it’s more than making everything flatter, even though that too, is a huge part of this hurdle. Instead, watchmakers have the monumental task of also being extremely space efficient — in a space that wasn’t very big to begin with. With clearances between components reduced to the minimum, even the smallest errors can become deal-breakers. 

And so the hallowed ranks have long been led by only a handful, namely Piaget and Bulgari, who for years have battled back and forth for the “world’s thinnest” titles. The Swiss-Italian rivalry, however, now has other brands like Audemars Piguet and Jaeger-LeCoultre to watch out for too. 

No thicker than a couple of credit cards, these ultra-thin watches have our votes for being technically and aesthetically astounding. We think the rest of your collection might be impressed too.

1
Bulgari Octo Finissimo Skeleton Ceramic

Although synonymous with wafer-thin movements and equally slim timepieces, Bulgari still knows how to make a big presence with their watches. The Octo Finissimo Skeleton Ceramic takes the baton from its slender predecessors by outfitting the high-performing timepiece with black ceramic, giving a whole new feel to the brand’s storied line.

The skeletonised version allows full view of the automatic calibre BVL 128SK within, a 2.23mm thick manual-winding movement that provides 65 hours of power reserve. The murdered-out case measures in at 5.5mm, which should sit flushed on your wrist with plenty of swag to spare. 

Case: 5.5mm

Movement: 2.23mm

2
Piaget Altiplano Ultimate 910P

It might have been upstaged by Bulgari as the world’s thinnest automatic watch after only a few months, but there’s still plenty to love about this ridiculously thin work of art. Using the same design and construction concepts as its equally slender predecessor, the Altiplano 900P, the watch sports all 238 components within its 4.30mm thick case, with some of the components being “barely thicker than a hair’s breadth”. 

The slightly asymmetric hours and minutes dial are integrated within the thickness of the caliber as opposed to being on top of it, and is protected by a glass that’s so thin that’s it’s been specially engineered to resist bending against the watch’s hands beneath.  

Case: 4.30mm 

3
Jaeger-LeCoultre Master Ultra Thin Kingsman Knife Watch

Specially adapted as an homage to the stylish agents in the blockbuster movie, this watch is a limited edition of 100 timepieces that takes its vintage cues from the celebrated 1907 “Couteau”. Like the pocket watch, this ultra-thin timepiece combines classic design with a razor-sharp case design, which even at its thickest point, only measures at 4.25mm thick. 

The winding crown at 12 o’clock is another highlight of the striking timepiece, protected by an arch-shaped loop that will no doubt spark plenty of conversations. Inside, the in-house hand-wound JLC 849 movement manages a reasonable 35-hour power reserve with a 21,600bph rate despite only measuring 1.85mm thick.

Case: 4.25mm

Movement: 1.85mm

4
Audemars Piguet Royal Oak Selfwinding Perpetual Calendar Ultra-Thin

Audemars Piguet has had a long history of making ultra-thin watches, but transforming a legend like the Royal Oak required plenty of finesse. The 41mm timepiece sees a departure from the usual “petite tapisserie” guilloché pattern that the brand has come to be known for, instead opting for a matte, vertically brushed dial that offers a cleaner backdrop against the tone-on-tone sub-counters.

At 6.3mm, the case is already 3.2mm thinner than a regular Royal Oak, thanks to the extra-thin 5133 which features innovations such as a floating barrel and a specially constructed rotor to keep thickness at a minimum.

Case: 6.3mm

Movement: 2.89mm

Shatricia Nair
Deputy Editor
Shatricia Nair is a motoring, watches, and wellness writer who is perpetually knee-deep in the world of V8s, tourbillons, and the latest fitness trends. She is fuelled by peanut butter and three cups of coffee a day.