My 3-year-old son was awarded a personal injury settlement last year. I am the trustee on his account, which he can access when he turns 18. I received a form 1099-INT interest form. It is in my name

Since the Form 1099-INT is reported under your social security number, then it should be included on your tax return.  You could then subtract the amount from your return by showing it was nominee interest.

To enter the 1099-INT form in TurboTax: 

1. On the top row of the TurboTax online screen, click on Search (or for CD/downloaded TurboTax locate the search box in the upper right corner). 
2. This opens a box where you can type in “1099-INT” (be sure to enter exactly as shown here) and click the magnifying glass (or for CD/downloaded TurboTax, click Find).
3. The search results will give you an option to “Jump to 1099-INT”
4. Click on the blue “Jump to 1099-INT” link.
5. Enter the 1099-INT and on the Tell us if any of these uncommon situations apply screen, select I need to adjust the taxable amount and Continue.
6. On the Report Interest Adjustment screen, enter your son's interest and select the Reason for Adjustment as I received all or part of this interest for someone else (I am a nominee) and Continue.

Your son may then have to file an income tax return. If your son had unearned income exceeding $2,100, he might be subject to the Kiddie Tax, and the income could be taxed at the parent's higher tax rate. https://ttlc.intuit.com/replies/3301446