How do I fix the rotation of an imported model?

Some 3D art packages export their models so that the z-axis faces upward. Most of the standard scriptsA piece of code that allows you to create your own Components, trigger game events, modify Component properties over time and respond to user input in any way you like. More info
See in Glossary in Unity assume that the y-axis represents up in your 3D world. It is usually easier to fix the rotation in Unity than to modify the scripts to make things fit.

If at all possible it is recommended that you fix the model in your 3D modelling application to have the y-axis face upwards before exporting.

If this is not possible, you can fix it in Unity by adding an extra parent transform:

1. Create an empty GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
   See in Glossary using the GameObject->Create Empty menu
2. Position the new GameObject so that it is at the center of your meshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
   See in Glossary or whichever point you want your object to rotate around.
3. Drag the mesh onto the empty GameObject

You have now made your mesh a Child of an empty GameObject with the correct orientation. Whenever writing scripts that make use of the y-axis as up, attach them to the ParentAn object that contains child objects in a hierarchy. When a GameObject is a Parent of another GameObject, the Child GameObject will move, rotate, and scale exactly as its Parent does. You can think of parenting as being like the relationship between your arms and your body; whenever your body moves, your arms also move along with it. More info
See in Glossary empty GameObject.