R42

R42 or R-42 may refer to:

Roads

 * R42 (Belgium)
 * R42 (South Africa)

Other uses

 * R42 (New York City Subway car)
 * HMS Undine (R42), a destroyer of the Royal Navy
 * Junkers R 42, a transport aircraft
 * R42: May cause sensitisation by inhalation, a risk phrase
 * Sidolówka, a Polish hand grenade
 * Spectre R42, a British sports car