4183 Cuno is an Apollo, Mars- and Venus-crosser asteroid. It was discovered in 1959 by Cuno Hoffmeister, from whom the asteroid takes its name.
Cuno is about 4–9 km in diameter and is an S-type asteroid, meaning that it is highly reflective and composed of nickel-iron mixed with iron- and magnesium-silicates.
In December 2000, Cuno was analysed by radar to determine its shape. The resultant images are lacking in detail, but indicate a rough sphere with some kind of concave depression 1–2 km in diameter.
4183 Cuno approaches the Earth to within 40 Gm six times in the 21st century. On 2012-May-20 Cuno made its closest Earth approach at a distance of 0.12182 AU (18,224,000 km; 11,324,000 mi). It will not make a closer approach until 2093.