Is my 2023 college grad a dependent

Yes, that would count as 5 months.  The IRS states "To qualify as a student, the person must be, during some part of each of any five calendar months of the year" 

I had similar question and found this response: 

Generally, a parent can claim your college student children as dependents on their tax returns. However, to claim a college student as a dependent on your taxes, the Internal Revenue Service has determined that the qualifying child or qualifying relative must:

• Be younger than the taxpayer (or spouse if MFJ) and:
  • Be under age 19,
  • Under age 24 and a full-time student for at least five months of the year.
• Or the child can be any age if totally and permanently disabled.
• Have lived with you for more than half the tax year. There are exceptions for temporary absences during the tax year, such as when your child is away at school.

https://www.hrblock.com/tax-center/filing/dependents/college-age-dependents-and-financial-support/#:~:text=However%2C%20to%20claim%20a%20college,five%20months%20of%20the%20year.