• Labiella Pfeiffer, 1854 accepted as Leptachatina Gould, 1847
• Laimella Cobb, 1920
• Libumella A.A. Luber ex A.F. Dibner, 1971 † (uncertain) [Phylum: Sporae dispersae]
• Libumella Rozhdestvenskaya in Chibrikova & Rozhdestvenskaya, 1959 † [Phylum: Arthropoda]
• Limella Rafinesque, 1815 accepted as Unio Philipsson, 1788
• Lobitella Monard, 1934
• Lubinella Opell, 1984
• Lublinella Gawor-Biedowa, 1987 † (uncertain) [Family: Sarcomastigota (awaiting allocation)]
• Lublinella Nehring-Lefeld, 1985 † [Family: Ostracoda (awaiting allocation)]
• Luciaella Fernández-Martínez & Tourneur, 1993 † (uncertain) [Order: Anthozoa (awaiting allocation)]
• Luciaella Gil de Pertierra, 2009 [Order: Proteocephalidea]
• Lucidella Swainson, 1840
• Luciella de Koninck, 1883 † [Family: Luciellidae]
• Luciella P.L. Mason, H.J. Jeong, R.W. Litaker, K.S. Reece & K.A. Steidinger in P.L. Mason et al., 2007 [Family: Pfiesteriaceae]
• Lucinella Monterosato, 1884
• Luisella Korshunova et al., 2017
• Lumicella Lu & Qin, 2013
• Luminella Kofoid & Campbell, 1939 accepted as Stenosemella Jörgensen, 1925
• Luniella Lasley, Klaus & Ng, 2015
• Luxiella Lecal, 1953