| Oakes, G Spencer | | Hill End/Tambaroora | C of E Minister (visiting) | |
| Oakes, John | | Tambaroora | Miner | 1852 |
| Oakes, Patrick | Teresa Ellen Giles | Crudine | Labourer | 1892 |
| Oakes, Patrick | Teresa Ellen Giles | Crudine | Grazier | 1900 |
| O'Brian | | Hill End | Mine Engineer | 1898-1908 |
| O'Brien, Catherine | | Hill End/Tambaroora | Widow | 1872 |
| O'Brien, Charles | Ellen Lee | Pyramul | Farmer | 1892 |
| O'Brien, Daniel | Ellen Board | Sallys Flat | Farmer | 1864-1888 |
| O'Brien, Daniel | Ellen Board | Sallys Flat | Shepherd | 1888 |
| O'Brien, James | | Sallys Flat | Miner | 1921 |
| O'Brien, James | | Sallys Flat | Shearer | 1923 |
| O'Brien, James Patrick | Mary O'Brien | Hill End | Carrier | 1872 |
| O'Brien, John | Mary Croake | "Commercial Hotel", Mudgee Rd, Tambaroora | Publican | 1857-1861 |
| O'Brien, Stephen | Ellen Dunleavy | Crudine | Farmer | 1888 |
| O'Connell, John | Theresa Cummins | Bank Chambers, Clarke St, Hill End | Doctor | 1872-1876 |
| O'Connell, John | Theresa Cummins | Hill End | Govt Medical Officer | 1874 |
| O'Connor, Denis J | Emily Levy Johnson | Hill End | Miner | 1875-1876 |
| O'Connor, Dennis | | Hill End/Tambaroora | Clerk | 1881 |
| O'Connor, Denny Joseph | Emily Levy Johnson | Hill End | Miner | 1873 |
| O'Connor, George | | Hill End | Miner | 1875-1876 |
| O'Connor, Johanna | Thomas O'Connor | Hill End | Midwife | 1880 |
| O'Connor, John | | Hill End/Tambaroora | Doctor | 1874-1877 |
| O'Connor, John | | Bowen St, Hill End | C of E Minister | 1875-1877 |
| O'Connor, John | | Church Lane, Hill End | C of E Minister | 1879 |
| O'Connor, John | | Belmore St, Hill End | C of E Minister | 1875 |
| O'Connor, Kate | John O'Connor | Hill End/Tambaroora | Dressmaker | 1875-1876 |
| O'Connor, Maxwell E | | Public School, Hill End | Relieving Teacher | 1956 |
| O'Connor, Thomas | | Hill End | Post & Telegraph Officer | 1875-1876 |
| O'Connor, Thomas snr | Johanna Donovan | Clarke St, Hill End | Fruiterer | 1875-1876 |
| O'Donnell, Hugh jnr | | Sofala Rd, Hill End | Farmer | 1872 |
| O'Donnell, Hugh snr | | Sofala Rd, Hill End | Farmer | 1872 |
| O'Donnell, James | | Hill End | Minister | 1886-1887 |
| O'Donnell, James | | Tambaroora | Teacher | 1913-1915 |
| Officer, George Hebden | Edith Sheila Clements | Hill End | C of E Minister | 1950-1951 |
| O'Flynn, Jerome E | Amber Lurlene Davidson | Hill End | Doctor | 1929-1937 |
| Ogle, Thomas | Elizabeth Farrell | Hill End | Carpenter | 1872 |
| O'Grady, John | Catherine Corcoran | Tambaroora | Miner | 1871 |
| O'Hare, M | Mary A Slattery | Sallys Flat | Grazier | 1936 |
| O'Here, Patrick | Winifred Ryan | Hill End | Baker | 1875-1876 |
| O'Keefe, Michael | | Sallys Flat | Settler | 1858 |
| O'Keefe, Michael | | "Strangers Home Hotel", Sallys Flat | Publican | 1867 |
| O'Keefe, Michael | | Unnamed hotel, Tambaroora Creek, Tambaroora | Publican | 1872 |
| Oldfield, Richard | | Teapot Swamp | Farmer | 1880 |
| Oliver, Charles | Elizabeth | Reef St, Hill End | Miner | 1873 |
| Oliver, Charles | Elizabeth | Red Hill, Hill End | Miner | 1876 |
| Oliver, Charles | Elizabeth | Hill End | Miner | 1872-1877 |
| Oliver, Charles | Elizabeth | Short St, Hill End | Miner | 1875-1877 |
| Oliver, L M | | Hill End | C of E Minister | 1921 |
| Oliver, Richard | | Hill End | Constable Police | |
| Oliver, W H | | Hill End | Miner | 1872 |
| Oliver, W T | Ellen Pearce ? | Hill End | Miner | 1892 |
| Oliver, William | Ellen Pearce | Hill End | Miner | 1886-1889 |
| Oliver, William Thomas | Ellen Pearce | Hill End | Miner | 1876-1878 |
| O'Loughlin, John | Ellen Kelly | Hill End | Miner | 1872 |
| O'Loughlin, M | | Hill End | Miner | 1875-1876 |
| Olver, Richard H | | Hill End | Constable Police | 1872 |
| Omant, James | Elizabeth Goodall | Hill End | Carrier/Carter | 1873 |
| Omart, James | Elizabeth Goodall | Hill End | Carrier/Carter | 1873 |
| On Gay & Co | | Mudgee Rd, Tambaroora | Storekeeper | 1872-1876 |
| On Gay & Co | | Clarke St, Hill End | Grocer | 1872-1907 |
| O'Neal, B | Kate Eliza O'Connor | Hill End | Miner | 1875-1876 |
| O'Neal, James | | Tambaroora | Butcher | 1869 |
| O'Neal, John | Rosina Parsons | Hill End | Miner | 1874 |
| O'Neil, Bernard | Kate Eliza O'Connor | Hill End | Miner | 1877-1879 |
| O'Neil, Graham | | Public School, Hill End | Assistant Teacher | Aft 1932 |
| O'Neil, James | | Newtown Gully, Hill End | Miner | 1872-1873 |
| O'Neil, Johanna | | Tambaroora | Residing | 1863 |
| O'Neil, John | Rosina Parsons | Brokenback, Hill End | Miner | 1874 |
| O'Neil, Patrick | | Tambaroora | Butcher | 1867-1876 |
| O'Neil, Thomas Joseph | Alice Norris | Hill End | Labourer | 1891 |
| O'Neill, John | | Newtown, Hill End | Miner | 1872 |
| Ongley, Edward | Maria Swannell | Sofala | Farmer | 1890 |
| Oram, Joseph | | Hill End/Tambaroora | Wesleyan Minister | 1870 |
| Ore, William Henshaw (Henry) | Evangeline (Eva) Symonds | Hill End | Poet | 1875-1876 |
| O'Reilly, James | | Hill End | Miner | 1886-1887 |
| O'Reilly, William | | Hill End/Tambaroora | Doctor | 1872 |
| O'Riley, Edward | Rose Pilley | Hill End | Miner | 1893-1898 |
| O'Riley, Joseph | Mary Cahill | Bald Hill, Hill End | Labourer | 1883 |
| O'Riley, Joseph | Mary Cahill | Hill End | Miner | 1873-1890 |
| O'Riley, Joseph | Mary Cahill | Hill End | Topman | 1889-1890 |
| O'Riley, Joseph | Mary Cahill | Bald Hill, Hill End | Farmer | 1900 |
| O'Riley, Luke | Mary Ann Northey | Hill End | Miner | 1898 |
| O'Rourke, John | | "Royal Hotel", Tambaroora Rd, Hill End | Publican | 1883-1884 |
| Osborne, James | Eliza Gustafson | Tambaroora St, Hill End | Draper | 1875-1884 |
| Osborne, John | | Hill End | Miner | 1875-1876 |
| Osborne, Thomas | | Hill End | Boot & Shoe Maker | 1875-1876 |
| Ottis, James | | Hill End/Tambaroora | C of E Minister | |
| Outlaw, Alfred | | Hill End | Miner | 1871 |
| Outlaw, Henry | Ann Ison | Bathurst Rd, Hill End | Miner | 1871-1873 |
| Owen, George | Emma Annie Buckland | Hill End | Wool Presser | 1883 |
| Owen, George Dunning | Emma Annie Buckland | Upper Pyramul | Miner | 1872-1874 |
| Owen, George Dunning | Emma Annie Buckland | Hill End | Miner | 1872-1880 |
| Owen, George Dunning | Emma Annie Buckland | Upper Pyramul | Shepherd | 1877 |
| Owens, George | | Newtown, Hill End | Clerk | 1889 |
| Owens, Hugh | Mary Ross | Hill End | Ostler | 1871 |
| Oxen, Marcus | Philemina Mary (Minnie) Bender | Hill End | Miner | 1869-1872 |
| Oxenham, Henry | Sarah Crane | Hill End | Miner | 1870-1872 |
| Oxenham, Phillip | Jane Hurst | Denison St, Hill End | Miner | 1870-1872 |