Maltby, WA has a population of 11,221 and is the 3,603rd largest city in the United States. The population density is 581 per sq mi which is 501% higher than the Washington average and 541% higher than the national average. The median age in Maltby is 43 which is approximately 15% higher than the Washington average of 38. In Maltby, 64% of the population over 15 years of age are married, 92% speak English and 2% speak Spanish. 56% of Maltby residents were born in Washington, 35% were born out of state, 2% were born outside of the United States and 7% were foreign born.