| Syllis aciculata (Treadwell, 1945) |
| Syllis aciculigrossa (San Martín, 1990) |
| Syllis adamantea (Treadwell, 1914) |
| Syllis alosae San Martín, 1992 |
| Syllis alternata Moore, 1908 |
| Syllis amica de Quatrefages, 1866 |
| Syllis annularis Verrill, 1900 |
| Syllis antoniae Salcedo-Oropeza, San Martín & Solís-Weiss, 2012 |
| Syllis armillaris (O.F. Müller, 1771) |
| Syllis barbata (San Martín, 1992) |
| Syllis bella (Chamberlin, 1919) |
| Syllis beneliahuae (Campoy & Alquézar, 1982) |
| Syllis bifurcata (Hartmann-Schröder, 1980) |
| Syllis botosaneanui (Hartmann-Schröder, 1973) |
| Syllis brasiliensis McIntosh, 1885 |
| Syllis broomensis (Hartmann-Schröder, 1979) |
| Syllis caeca Monro, 1933 |
| Syllis castroviejoi Capa, San Martín & López, 2001 |
| Syllis catenula Verrill, 1900 |
| Syllis clavata Claparède, 1863 |