| Navicula brachium Hust., 1944 |
| Navicula brasiliensis Grunow, 1863 |
| Navicula brevissima Hust., 1937 |
| Navicula campylodiscus Grunow, 1875 |
| Navicula canalis R.M. Patrick, 1944 |
| Navicula cancellata Donk., 1872 |
| Navicula capitata Ehrenb., 1838 |
| Navicula capitatoradiata Germain, 1981 |
| Navicula cari Ehrenb., 1836 |
| Navicula cari var. angusta (Grunow) Grunow, 1885 |
| Navicula cari var. cari Ehrenb., 1836 |
| Navicula cari var. cincta (Ehrenb.) Lange-Bert., 1980 |
| Navicula cari var. recens Lange-Bert., 1980 |
| Navicula caribaea Cleve, 1874 |
| Navicula carinifera Grunow, 1874 |
| Navicula caroliniae Bahls, 2012 |
| Navicula challengeri Grunow, 1880 |
| Navicula charlatii M. Perag., 1921 |
| Navicula cincta (Ehrenb.) Ralfs, 1861 |
| Navicula cincta var. cari (Ehrenb.) Cleve, 1895 |