Obrien, Michael (280 acres): s23-t40-r17 Osage twp. (1859)

Obyrne, Thomas (40 acres): s35-t42-r17 Moreau twp. (1859)

Oconner, John (40 acres): s27-t41-r18 Buffalo twp. (1859)

Odell, Jeremiah C. (40 acres): s28-t42-r18 Hawcreek twp. (1837)

Odonald, John (200 acres): s10-t40-r17 Osage twp. (1859)

Odonohue, James (80 acres): s17-t40-r17 Osage twp. (1859)

Oehrke, August (80 acres): s32-t43-r19 Hawcreek twp. (1854)

Oglesby, Jacob (160 acres): s17-t43-r16 Moreau twp. (1840) | s20-t43-r16 Moreau twp. (1840)

-----, John (80 acres): s17-t43-r16 Moreau twp. (1840) | s20-t43-r16 Moreau twp. (1840)

-----, Pleasant B. (80 acres): s9-t45-r19 Richland twp. (1840)

Ohaver, H. C. (40 acres): s8-t42-r19 Hawcreek twp. (1857)

-----, Henry C. (40 acres): s31-t42-r19 Hawcreek twp. (1859)

-----, James (40 acres): s24-t42-r16 Moreau twp. (1856)

Ohawer, John T. (40 acres): s35-t43-r16 Moreau twp. (1848)

Ohlrogge, John (105.51 acres): s6-t43-r19 Hawcreek twp. (1845)

Okeefe, William (98.21 acres): s18-t40-r16 Osage twp. (1859)

Oneil, Thomas (40 acres): s11-t44-r19 Richland twp. (1848)

Oreilly, Thomas (40 acres): s27-t42-r16 Moreau twp. (1859)

Orr, Mark (160 acres): s21-t41-r18 Buffalo twp. (1859)

Orth, Lewis (360 acres): s8-t42-r18 Hawcreek twp. (1859)

Otten, Claus H. (120 acres): s14-t44-r19 Richland twp. (1856)

-----, Henrich (79.34 acres): s1-t43-r19 Hawcreek twp. (1859) | s36-t44-r19 Richland twp. (1859)

-----, Henry (118.17 acres): s1-t43-r19 Hawcreek twp. (1857) | s17-t43-r19 Hawcreek twp. (1848) | s36-t44-r19 Richland twp. (1857)

-----, Hinrich (80 acres): s36-t44-r19 Richland twp. (1857)

Ousley, Robert (120 acres): s19-t45-r18 Millcreek twp. (1840) | s20-t45-r18 Millcreek twp. (1840)

Ownbey, Archibald (38.56 acres): s19-t40-r16 Osage twp. (1921)

-----, Nicholas (102.32 acres): s19-t40-r16 Osage twp. (1833)

Owsley, Henry (40 acres): s18-t45-r18 Millcreek twp. (1843)

-----, Robert (80 acres): s28-t45-r18 Millcreek twp. (1857)