Can I Potty Train my Child at 18 Months? Yes, yes, and yes! Those sphincter muscles are fully developed at around 18 months of age, which means your little one can be potty trained successfully. My kiddos all sported fancy Dora, Elmo or Princess undies at 18 months. Now, I started potty training all my … Continue reading Can I Potty Train my Child at 18 Months?