Carnival Monday in Argentina is a part of their grand annual carnival celebration, falling within late February or early March. This public holiday forms a long weekend that offers Argentinians the chance to participate in, or simply enjoy, the diverse festivities. The carnival celebrations, along with Carnival Monday, usually take two days, including the preceding Sunday - Carnival Sunday.

On Carnival Monday, one can witness lively parades and street parties across Argentina. Communities come together to enjoy music, dance, and the vibrant colours of costumes and floats. The celebrations reflect a fusion of cultural influences, from indigenous tradition to European, African, and gaucho customs. Some of the most famous celebrations take place in Gualeguaychu, Entre Rios province, where the carnival transforms the city into a spectacle of music, rhythm, colour, joy, and brilliance.

While Carnival Monday is a time of jubilant celebration, it also carries cultural and historical significance. The celebration has its roots in ancient pagan rituals, but was later adopted by the Catholic Church as a final celebration before the commencement of Lent. Nowadays, it's seen more as a national holiday that serves as an expression of cultural identity and unity. Whether it's through watching or participating in the parades, or simply enjoying the general atmosphere, Carnival Monday offers locals and tourists alike a unique glimpse into Argentine culture.