Is Nikon D3500 and Canon EF 300mm f/2,8 L USM compatible?

Below you will find your chosen camera and lens. Click on the product name for more information.

Buy	Nikon D3500 Released: 2018 Type: Digital SLR Sensor: DX / APS-C (1.5x) 24 Megapixels 6000 x 4000 pixels
Buy	Canon EF 300mm f/2,8 L USM Released: 1987 Telephoto Lens (prime) Focal Length: 300 mm Aperture: f/2,8

Can you combine these two?

This is the short answer:

No! This combination is not compatible

The camera and lens you have chosen cannot be combined. Here is a longer answer:

A non-Nikon lens on a Nikon camera

This is a Canon lens and unfortunately they are not constructed to work with Nikon cameras. If the lens would have been a Sigma, Tamron och Tokina it would perhaps be different since they are available with a compatible Nikon mount.