Yes, you can say “Happy Veterans Day” to active-duty service members, but consider a few nuances:

• Context matters: In the United States, Veterans Day honors all who served; active-duty personnel are typically recognized on Armed Forces Day (May) or during appropriate occasions. On Veterans Day itself (November 11), many people express appreciation to all veterans and service members, including those currently serving.
• Short and respectful options:
  • “Happy Veterans Day.”
  • “Thank you for your service.”
  • “Happy Veterans Day to all who have served, including those currently serving.”

If you want a more formal or personalized message, you could say:

• “Happy Veterans Day. Thank you for your dedication and service.”
• “Wishing you a meaningful Veterans Day. I’m grateful for your service.”

Would you like this phrased for a card, a social post, or a spoken greeting?