Nica or NICA may refer to:
- Nīca, a village in Latvia
- Nica, the name in some languages of Nice, a French city
- "Nica", a jazz tune composed by Sonny Clark
- Nica is an adjective which may refer to:
- Nica (name)
- National Iranian Canadian Assembly
- Nica Airlines, an alternate name for Nicaragüense de Aviación, a Nicaraguan airline
- National Institute of Circus Arts, an Australian circus school
- National Intelligence Coordinating Agency, a government agency in the Philippines
- Nica (butterfly), a genus of nymphalid butterflies in the Biblidinae subfamily
- National Ice Carving Association, a U.S. ice sculpture association
- Netherlands Indies Civil Administration, the World War II-era Dutch colonial administration in Indonesia
- Nicotine Anonymous (NicA), a stop-smoking program
- Northern Ireland Court of Appeal, part of the Courts of Northern Ireland
- Nuclotron-based Ion Collider fAcility, a proton and heavy ion collider under construction at JINR in Dubna, Russia