Causus defilippii, also known commonly as the snouted night adder, is a species of venomous snake in the subfamily Viperinae of the family Viperidae.

[3][4][5][6] The specific name, defilippii, is in honor of Italian zoologist Filippo De Filippi.

The circumorbital ring consists of 1–2 preocular scales, 1–2 postoculars and 1–2 suboculars that separate the eye from the supralabials.

The belly is yellowish while, uniformly colored or with scattered small grayish brown spots.

[5] The snouted night adder is found in Tanzania and the Democratic Republic of the Congo southward through Malawi, Zambia, Mozambique, and Zimbabwe to South Africa and Eswatini.

[2] C. defilippii occurs in moist and dry savanna, coastal thickets, and forests from sea level to around 1,800 m (5,900 ft) altitude.

[8] It favors moist surroundings, but has also been found in dry areas on rocky hillsides and escarpments.

[5] Little is known about the venom of C. defilippii, but the symptoms described in the few existing case histories include rapid swelling, fever, sometimes intense pain, and occasionally lymphadenopathy.