As has been said in some comments, 135 film is just one long strip of photo-sensitive film. The size of exposed frames (and consequently the aspect ratio) depends on the camera in use; it is not predetermined.
The vast majority of cameras expose frames measuring 36mm × 24mm, an aspect ratio of 3:2, and you will not easily find cameras giving a different aspect ratio. However...
The Hasselblad XPan is pretty unique in that it has two selectable frame sizes - standard 36mm × 24mm or panoramic frames measuring 65mm × 24mm. (In order to cover the 65mm width of film, the XPan's lenses project a much larger image circle than is normally the case for lenses for 135 film.)
There are rotating-lens panoramic cameras such as the Noblex (exposing frames measuring 66mm × 24mm), Widelux (which exposes frames measuring 56mm × 24mm) and Horizon from Lomography (58mm × 24mm frames I think). These take in a really wide angle of view, but the rotating lens has the side-effect of bending lines that should appear straight. I have a Noblex camera and love some of the images I get from it. The actor Jeff Bridges uses a Widelux camera, and some of his "behind the scenes" photos from the movie sets he works on make really interesting use of the panoramic format.
Of course, to get usable images from 135 film, there's a two-step process of developing and printing, or developing and scanning. Developing film that was exposed in any of the aforementioned panoramic cameras is no problem - the film can be developed anywhere that develops 135 film. But printing can be an issue because of the "non-standard" width of the frames. The most straightforward way to proceed is probably to scan the developed film yourself. Frames from the Widelux (and I presume the Horizon) have the advantage of fitting into a 6×6 enlarger, if darkroom printing is important.
When the APS format took off in the second half of the 1990s, one of its main selling points was its panoramic mode. This was a contrivance really, because these panoramic frames were just standard frames with the top and bottom chopped off. The exact same effect can be achieved by printing any photo to larger dimensions and cropping the print to a 3:1 ratio. In any case, some camera manufacturers implemented the same feature in some cameras using 135 film, so it is possible to find cameras that will expose a 3:1 ratio image with the same 36mm width as standard frames. (With these "pseudo-panoramic" frames, the top and bottom of the standard frame are physically masked off to achieve the 3:1 ratio exposure, whereas in the case of APS, the full frame was exposed but only a 3:1 ratio strip was printed.) I know Minolta had a few models with the feature - look for cameras with panorama in the name here: https://en.wikipedia.org/wiki/List_of_Minolta_products. They also had a point-and-shoot model called Riva Panorama that exposed every frame through the 3:1 panorama mask, and there were also disposable cameras available that did the same thing.
There are also "half-frame cameras" such as the original Pen series from Olympus. These expose frames half the size of standard frames, i.e. 24mm × 18mm, giving them an aspect ratio of 4:3.
I think the options here are really your main options for native aspect ratios other than 3:2 with 135 film. There are "612" cameras that use 120 film and have a 2:1 aspect ratio, but obviously medium format is a different ball game.
If you want to experiment with aspect ratios wider than 3:2, but are not looking for a dedicated panoramic camera, try simply using a wide-angle lens and cropping your resulting photo to any aspect ratio you think looks appealing.