| Navicula gelida Grunow, 1884 |
| Navicula gemmata Grev., 1859 |
| Navicula gemmatula Grunow, 1875 |
| Navicula gibba (Ehrenb.) Kütz., 1844 |
| Navicula giebelii A. Schmidt, 1875 |
| Navicula globiceps (Greg.) Ralfs, 1861 |
| Navicula goeppertiana (Bleisch) Sm., 1876 |
| Navicula gracilis Ehrenb., 1838 |
| Navicula gracilis var. gracilis Ehrenb., 1838 |
| Navicula gracilis var. radiosa (Kütz.) Rabenh., 1847 |
| Navicula graeffii Grunow, 1875 |
| Navicula granulata Ehrenb., 1836 |
| Navicula gregaria Donkin, 1861 |
| Navicula gregaria var. thurholmensis (J. -Danff.) Cleve, 1894 |
| Navicula grevilleana Hendey, 1964 |
| Navicula grevilleoides Hust., 1962 |
| Navicula grimmei Krasske, 1930 |
| Navicula gruendleri (Cleve & Grunow) Cleve, 1895 |
| Navicula hagelsteinii Hust., 1962 |
| Navicula halophila (Grunow) Cleve, 1894 |