Governor Suebsak Iamwicharn presided at the ceremony at the Muang Mae Hong Son District Office.
He said the 417 were born stateless to foreigners who had migrated to Mae Hong Son.
Photo from: Mae Hong Son Wan Nee's Facebook Fanpage
The Interior Ministry allows such people to be considered for citizenship on a case-by-case basis.
Members of this group live in tambons Pang Moo, Mok Champae, Jong Kham, Phabong, Huay Pha and Huay Pong in Muang district.
Suebsak said their applications for citizenship were endorsed by 32 non-governmental organisations that assist stateless people in the North.
The Interior Ministry had earlier approved citizenship for other young stateless people elsewhere in Mae Hong Son and continues to accept applications.
Kanchanaburi on Monday granted citizenship to 342 ethnic Karen children and young people.