Miami Valley (Central Southwestern Ohio) Naturalization Records Indexes for Auglaize County (1840-1906), Champaign County (1820-1956), Clark County (1820-1906), Darke County (1814-1928), Greene County (1831-1954), Logan County (1821-1906), Mercer County (1814-1906), Miami County (1814-1906), Montgomery County (1803-1931), Shelby County (1814-1906)
Cincinnati - see Hamilton County below
Cleveland Area:
Ohio Naturalization Petition and Record Books, 1907-1946 (at Ancestry/requires payment) includes scanned images from National Archives microfilm publication M1995 (Naturalization Petition and Record Books for the U.S. District Court for the Northern District of Ohio, Eastern Division, Cleveland, 1907-1946)