Is the Nikkor 70-300mm F/4.5-5.6 Lens compatible with the Nikon D40 camera body?

I was wondering if the Nikkor 70-300mm F/4.5-5.6 Lens was compatible with the Nikon D40 body because it says the mount is a Nikon F mount.

Yes it is compatible. As to whether it would autofocus with the D40 is another matter.

This one? Http://www.nikonusa.com/Nikon-Products/Product/Camera-Lenses/2161/AF-S-VR-Zoom-NIKKOR-70-300mm-f%252F4.5-5.6G-IF-ED.html YES that one is compatible with your camera.
If it has G after it, it will work with the D40 and focus.
All of the nikon lenses will work on the D40, but the ones without the motor in them won't auto focus.

Yes its compatible to all nikon dslr cameras.

Yes its compatible. The AF-S VR Zoom-NIKKOR 70-300mm f/4.5-5.6G IF-ED Telephoto Zoom Lens from Nikon is a high-performance telephoto zoom lens that has been designed to meet the demands of both digital and 35mm format SLR users. It offers a 4.3x zoom with a range of 70-300mm (equivalent 105-450mm on a DX Nikon D-SLR) and features ED (Extra-low Dispersion) glass elements that ensure superior optical performance.

Wondering if nikon AF NIKKOR 70-300MM 1:4-5.6 G Compatible with nikon D5100?