Can I take 100 mg of modafinil and 25 mg of Zoloft at the same time every day?

Hi, Lrp!
Yes, you probably can but you might want to double check with your doctor or pharmacist.
This is the Interactions Checker report:
https://www.drugs.com/interactions-check.php?drug_list=2057-1348,1647-0
"No interactions were found between your selected drugs. This does not necessarily mean no interactions exist. Always consult your health care provider."
Best regards,
Wildcat