Where on my tax form can I claim Mileage?

[rjs]

Mileage for what?

For a job where you get a W-2?

For your own business or self-employment?

For medical treatment?

For volunteering for a charity?

For traveling to military reserve duty?

[TeresaM]

Mileage may be claimable if for business, charitable, or medical purposes.  
It will be entered in the section of the return for the type of mileage. 
It will be in the Self-employment income and expenses section for business use, under Wages and Income, or in the  Medical or Charitable Donations section of Deductions and Credits.