This is an non-curated collection, so quality varies massively. The above link is directly to the 3D objects section. OpenGameArt is a repository for free assets aimed at game developers. The link above links directly to the free models, you can then filter down by addition requirements (rigged, poly count, etc)

TurboSquid is one of the oldest model resources on the internet and has a huge collection of free assets. Products are freely usable in personal and commercial projects as long as you use Unreal Engine.

The above link searches for just free content. The majority of free content is directly from Epic, but is of an exceedingly high quality. The Unreal Engine asset store is a fraction of the size of the Unity store. You can then filter by price, including $0 as an option. To limit to just free models, go to the 3D category and search for something.

Just because you found a freely available Boba Fett model with a commercial license, doesn’t mean you can use it in a commercial project! Existing copyright and trademark laws still apply. Also be careful to respect copyright laws. Also keep in mind that you will see these assets commonly in asset flips due to their direct integration with their collective game engine. Generally the license limits you to use those assets in those engines. If you are using a game engine, specifically Unity and Unreal, both host several free models for download. If I’ve missed a resource you use, please let me know in the comments down below. Perhaps you are a bit artistically challenged, or you are looking for resources to prototype your 3D games? Where can you find the best free 3D models? This page is a collection of some of the best resources for 3D models with permissive licenses.

Unity 3d assets free download