There are 29.5735 milliliters in one US fluid ounce.

Quick Reference:

• 1 US fluid ounce = 29.5735 mL
• 1 UK (Imperial) fluid ounce = 28.4131 mL

If you need to convert ounces to milliliters, just multiply the number of ounces by 29.5735 (for US fluid ounces).