The MAXXI (Italian: Museo nazionale delle arti del XXI secolo, National Museum of the 21st Century Arts) is a national museum of contemporary art and architecture in the Flaminio neighborhood of Rome, Italy. The museum is managed by a foundation created by the Italian ministry of cultural heritage. It was designed as a multidisciplinary space by Zaha Hadid and committed to experimentation and innovation in the arts and architecture.
The project was first announced in 2000 and took over 10 years to complete, during which time there have been six changes of national government in Italy.
The design of Zaha Hadid was the winner of an international design competition. The site of the new museum was that of a disused military compound, the former Caserma Montello. The competition proposal by Zaha Hadid envisaged the construction of five new structures, only one of which has been actually built. 
The art installation and the opening of MAXXI, in 2010, were photographed by Simone Cecchetti, who was chosen from national photography competition.
The Royal Institute of British Architect’s (RIBA) 2010 Stirling Prize for architecture has been awarded to MAXXI. In its 15th year, the award is presented annually for the best new European building, built or designed in Britain, judged to have made the greatest contribution to the evolution of British architecture.
The building is a composition of bending oblong tubes, overlapping, intersecting and piling over each other, resembling a piece of massive transport infrastructure.
The structure of the new building of the museum is composed of curved side walls made in self-consolidating concrete, the horizontal structures are mostly made of black-painted steel profiles, sometimes clad with fiber-reinforced concrete panels, as for the roof trusses. 
The MAXXI consists of two museums: "MAXXI art" and "MAXXI architecture". In addition to the two museums, the MAXXI also features an auditorium, a library and media library specialized in art and architecture, a bookshop, a cafeteria, a bar/restaurant, galleries for temporary exhibition, performances, educational activities. The large public square designed in front of the museum is planned to host art works and live events.
The outdoor courtyard surrounding the museum provides a venue for large-scale works of art.
The permanent collections of these two museums grow through direct acquisitions, as well as through commissions, thematic competitions, awards for young artists, donations and permanent loans.
The collection includes works by Alighiero Boetti, Grazia Toderi, William Kentridge, Kara Walker, Ed Ruscha, Gilbert & George, Gino De Dominicis, Michael Raedecker, Anish Kapoor, Gerhard Richter, Francesco Clemente, Lara Favaretto, Marlene Dumas, Maurizio Cattelan, Gabriele Basilico, Kiki Smith, Thomas Ruff, Luigi Ghirri, Manfredi Beninati, Vanessa Beecroft, Stefano Arienti, Francis Alys, Ugo Rondinone, Thomas Schutte, Francesco Gostoli and archives of architects Carlo Scarpa, Aldo Rossi and Pier Luigi Nervi.
- Jonathan Glancey: Zaha Hadid's stairway into the future, in The Guardian, 16 November 2009, retrieved 5 July 2010
- Riccardo Bianchini. "Zaha Hadid – The MAXXI Museum Rome – part 1". Inexhibit. Retrieved December 5, 2015.
- Rome’s MAXXI
- Rowan Moore: "Zaha Hadid's new Roman gallery joins the pantheon of the greats", in The Guardian, 6 June 2010, retrieved 5 July 2010
- Riccardo Bianchini. "Zaha Hadid – The MAXXI Museum Rome – part 2". Inexhibit. Retrieved December 5, 2015.
- Fondazionemaxxi, retrieved 5 July 2010
- Junkin, Caitlin. "At Maxxi in Rome, Urban Gardens Bloom," New York Times. September 16, 2011; excerpt, "Natural and recyclable materials like pressed hay, soil and grass were used in construction of the archipelago, rendering an organic touch to the museum’s concrete areas"; retrieved 2011-09-28.