The Greens (Montenegrin: Zelenaši/Зеленаши) were a group of Montenegrin separatists, most notable for instigating the Christmas Uprising of 1919, and for trying to re-establish the Kingdom of Montenegro as an Axis client state during World War II.
The Greens drew their membership from the highland tribes (Moračani, Piperi, and Rovci), the Katun clans (Bjelice, Cetinje, Cveto, and Cuce), and the Herzegovinian tribes (Nikšići and Rudinjani). They declared themselves as Serbs. They originally existed from 1918 to 1926 in Montenegro in the newly established Kingdom of Serbs, Croats, and Slovenes, when they supported the House of Petrović-Njegoš of Montenegro over the House of Karađorđević of Serbia, and were opposed to the mode and manner in which the south Slavic unification was implemented, resulting in the disappearance of Montenegro as a political entity.
Greens tended to emphasize the key role of Montenegro in Slavhood and many favoured a federal Yugoslavia. Notable leaders of the Greens included Krsto Zrnov Popović,Jovan S. Plamenac and Novica Radović.