Surname ถนอมสินธุ์ (ถนอมสินธุ์ 
) , all over the world, is a very rare last name. The family name ถนอมสินธุ์ is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname. Much less frequently, ถนอมสินธุ์ is the forename as well as the last name.