- O'Brian, James
- O'Brien Consolidated Industries
- O'Brien, Albert
- O'Brien, Bridget
- O'Brien, Celia
- O'Brien, Cornelius
- O'Brien, Daniel
- O'Brien, Dennis
- O'Brien, Dick
- O'Brien, Edward
- O'Brien, Francis
- O'Brien, J.F.
- O'Brien, James
- O'Brien, James A.
- O'Brien, Jeannette
- O'Brien, John
- O'Brien, John J.
- O'Brien, Julia
- O'Brien, Kate
- O'Brien, Laurence
- O'Brien, Lillian Caron
- O'Brien, Mae
- O'Brien, Maggie
- O'Brien, Martin
- O'Brien, Mary
- O'Brien, Maurice
- O'Brien, Michael
- O'Brien, Patrick
- O'Brien, Peter
- O'Brien, Richard
- O'Brien, Rose
- O'Brien, Sarah
- O'Brien, Therese
- O'Brien, Walter
- O'Brien, William
- O'Brine, Patrick
- O'Brion, Alton
- O'Callahan, Mr.
- O'Callahan, Timothy
- O'Claire, Lena
- O'Connel, --Mr.
- O'Connel, James
- O'Connell and Co.
- O'Connell, Bill
- O'Connell, Bishop
- O'Connell, C.
- O'Connell, Catherine
- O'Connell, Con
- O'Connell, Corneleus
- O'Connell, Craig
- O'Connell, Daniel
- O'Connell, Dennis
- O'Connell, Edward
- O'Connell, Elizabeth
- O'Connell, George
- O'Connell, Hannah
- O'Connell, J.
- O'Connell, James
- O'Connell, Johanna
- O'Connell, John
- O'Connell, Kate
- O'Connell, Louis
- O'Connell, Lucy
- O'Connell, Lucy Dr.
- O'Connell, M.
- O'Connell, Mary
- O'Connell, Maurice
- O'Connell, Michael
- O'Connell, Morris
- O'Connell, P.H.
- O'Connell, Patrick
- O'Connell, Timothy
- O'Connell, William
- O'Connell, William, Bishop
- O'Connor, Daniel
- O'Connor, Helen
- O'Connor, Joanna
- O'Connor, John
- O'Connor, Matthew
- O'Connor, Michael
- O'Connor, Patrick
- O'Connor, Timothy
- O'Darrington, Patricia
- O'Donnell, Honora
- O'Donnell, John
- O'Donnell, M.A. (Miss)
- O'Donnell, Maggie
- O'Donnell, Margaret
- O'Donnell, Mrs.
- O'Donnell, Patricia
- O'Donnell, Patrick
- O'Donnell, Roger
- O'Donnell, Thomas
- O'Donnell, William
- O'Donnell, Winfred
- O'Duggan, Terrance
- O'Gorman, O.
- O'Hara, D.
- O'Hara, Gladys
- O'Hearn or A'Hearn, Patrick
- O'Hearn, Bridget
- O'Hearn, James
- O'Hearn, John
- O'Hearn, Kate
- O'Hearn, Thomas
- O'Kane, James
- O'Laughlin, Francis
- O'Leary, A.
- O'Leary, Daniel
- O'Leary, Dennis
- O'Leary, Michael
- O'Leary, Patrick
- O'Leary, Thomas
- O'Leary, Timothy
- O'Morrill, C., Mrs.
- O'Neal, --
- O'Neal, John
- O'Neal, Mary
- O'Neil, Daniel
- O'Neil, John
- O'Neil, Madeline
- O'Neil, Mark
- O'NEil, Maurice
- O'Neil, Patrick
- O'Neill, Norah A.
- O'Neill, Thomas J. Mrs.
- O'Regan, Michael
- O'Reilly, James
- O'Rourke, John
- O'Ryan, Leary
- O'Shaughnessey, Michael
- O'Sullivan, James P.
- O'Sullivan, Jim
- O'Sullivan, Mary
- Oak Hill Cemetery
- Oak Park
- Oak Street Training School
- Oak, George
- Oakdale Auto Co.
- Oakes, -- Dr.
- Oakes, David D.
- Oakes, Ella
- Oakes, Gracia A.
- Oakes, H.W.
- Oakes, Henry W.
- Oakes, John
- Oakes, Ruth
- Oakes, S. Dr.
- Oakes, Silvester
- Oakes, Vance
- Oakes, W.K.
- Oakes, Wallace K.
- Oakes, Wallace K., Mrs.
- Oaks, George Mrs.
- Oaks, Wallace K., M.D.
- Oasis Soup Kitchen
- Ober, Bentley W.
- Obertson, Morgan
- Obie, Cindy Ann
- Obie, Henry
- Obie, Marcel
- Obie, Thomas
- Obin, H. Mrs.
- Occupational Training Center for the Intellectually Handicapped
- Occupations--Androscoggin County (ME)
- Occupations--Lewiston (ME)
- Odd and Unusual
- Odd Fellows
- Odd Fellows Androscoggin Lodge
- Odd Fellows Asylum Lodge
- Odd Fellows Block
- Odd Fellows Celebration
- Odd Fellows Golden Rule Lodge
- Odd Fellows Hall
- Odd Fellows Home
- Odd Ladies
- Odlin, Abbie S.
- Odlin, Eva F.
- Odlin, Fred L., Detective
- Odlin, Frederick
- Oeilleuse, George
- Offner, Elliot
- Ogden, Joseph
- Ogier, Edward
- Ogilvie, Jennie
- Oiknine, Jack J.
- Oiseau de Neige
- OKay Club
- Old Boys' Dancing Class
- Old Canada Road
- Old Catholic Church on Lincoln St.
- Old Colony Trust Co.
- Old Engine House
- Old Home Day
- Old Kora Temple
- Old Ladies' Home
- Old man of the falls (Rock formation)
- Old Orchard Beach Pizza
- Old South Baptist Church
- Old Town, Me -- Franco-American community