Mongonui and then Mongonui and Bay of Islands was a former parliamentary electorate in the Far North District in the Northland region of New Zealand, from 1861 to 1881.
Mongonui was represented by three Members of Parliament:[2]
| Election | Winner | |
| 1861 election | William Butler (Independent) | |
| 1866 election | Thomas Ball (Independent) | |
| 1870 by-election | Thomas Gillies (Independent) | |
Mongonui and Bay of Islands was represented by three Members of Parliament from 1871 to 1881.[2]
| Election | Winner | |
| 1871 | John McLeod (Independent) | |
| 1873 by-election | John William Williams (Independent) | |
| 1876 | ||
| 1879 | John Lundon (Independent) | |