Could Duncan be the perfect name for your baby boy? The baby boy name Duncan is 6 letters long, and contains 2 vowel(s) and 4 consonant(s). Duncan is a baby boy name that starts with the letter D and ends in the letter N. The baby boy name Duncan has a popularity of 2% and is ranked 978 in the list of top 1000 most popular baby boy names. If Duncan isn't the ideal name for your baby boy then take a look here for some randomly generated names. Hopefully you'll find a more suitable first name for your baby boy than Duncan!