Pan American Unity is a mural painted by Mexican artist and muralist Diego Rivera for the Art in Action exhibition at Treasure Island's Golden Gate International Exposition (GGIE) in San Francisco, California in 1940. This work was the centerpiece of the Art In Action exhibit, which featured many different artists engaged in creating works during the Exposition while the public watched.

Pan American Unity, a true fresco, was painted locally in San Francisco on commission for San Francisco Junior College during the second session of GGIE, held in the summer of 1940. At the time of the mural commission, college leadership had planned on installing it at the yet-to-be-built Pflueger Library after the closing of the 1939–1940 GGIE. Pflueger had designed the library with the intent that Rivera's mural would cover three walls; the mural as-completed would be mounted on the south wall of the library's reading room, and Rivera intended to return once the library was complete to add murals to the west and east walls. Both the San Francisco Art Commission and Board of Education received protests over the mural's content before its completion, primarily because of the included caricatures of Adolf Hitler and Benito Mussolini. The Art Commission approved the artistic merit in August 1940 but deferred the judgement of appropriate subject matter to the Board of Education. Pflueger announced that Rivera would continue to work on the mural for "at least another week" after the close of GGIE.

Rivera completed the mural three months after the close of GGIE, and 32,000 automobiles came to Treasure Island with up to 100,000 visitors to view the completed work on Sunday, December 1. The mayor of San Francisco, surveying the crowd, quipped "This Rivera is more popular than Wendell Willkie." The San Francisco Arts Commission accepted the mural in January 1941. After its showing in early December, the mural was crated and stored on Treasure Island.

While in storage, the de Young Museum declined to take the mural in 1941, as it was too large to move conventionally; the US$4,800 (equivalent to $100,000 in 2023) cost to lower the panels through a skylight was cited as the reason to decline it. That year, while extinguishing a hangar fire on Treasure Island, one of the crates was pierced by a fireman's axe, leaving a 20 in (510 mm) gash near the portrait of Sarah Gerstel in Section 5. Pflueger wrote to Rivera, who offered to repair the damage, but he never had the opportunity. The crated pieces were moved into storage at the college in June 1942, next to the men's gym. Emmy Lou Packard, Rivera's primary assistant on the mural, examined the damage but did not repair it at the time, instead choosing to wait for the installation of the mural in the library. However, with the start of the Second World War, the construction of the library was postponed to save materiel for wartime manufacturing, and after Pflueger's death in 1945, shelved indefinitely.

After Milton Pflueger (the younger brother of Timothy) was given the commission to design the CCSF campus theater in 1957, he proposed his initial design for the theater lobby should be expanded to accommodate the mural in the new facility. Emmy Lou Packard returned to repair the damage after the theater was completed in 1961, and Mona Hoffman, another one of Rivera's assistants on the original work was unable to distinguish the repair, to Packard's delight.

The current library at CCSF, which opened in 1995, was designed with a four-story atrium to hold the mural, but it was not moved amid concerns of potential damage. In 1999, a Getty Conservation Institute expert chided college personnel to consider the next two hundred years, and the artist's daughter, Guadalupe Rivera Marín challenged CCSF to construct a building dedicated to the mural. A conceptual building was designed by Jim Diaz of KMD Architects in 2012 to house the mural.

The mural was created on 10 robust steel-framed panels bolted together and weighing about 23 short tons (21 t) in total. It was deliberately designed to be portable, as it would have to be moved to the college campus from Treasure Island after completion, and others have speculated Rivera made it portable after the destruction of Man at the Crossroads. At 22 ft × 74 ft (6.7 m × 22.6 m), it is his largest contiguous work and it completely spans the narrow lobby of the college's Diego Rivera Theater.

Rivera was assisted in the project by Thelma Johnson Streat, an African-American artist and textile designer. Life magazine also noted the assistance of Mona Hoffman, and Rivera later wrote a letter to the editor crediting Emmy Lou Packard and Arthur Niendorff as his chief assistants.

The formal title of the piece, as given by Rivera is Unión de la Expresión Artistica del Norte y Sur de este Continente (The Marriage of the Artistic Expression of the North and of the South on this Continent) , but it is more commonly referred to as Pan American Unity. During a 1940 interview Diego Rivera was quoted as saying,

"I believe in order to make an American art, a real American art, this will be necessary, this blending of the art of the Indian, the Mexican, the Eskimo, with the kind of urge which makes the machine, the invention in the material side of life, which is also an artistic urge, the same urge primarily but in a different form of expression."

— Diego Rivera

He later elaborated "American art has to be the result of a conjunction between the creative mechanism of the North and the creative power of the South coming from the traditional deep-rooted Southern Indian forms." Rivera felt that artists in North America should be inspired by New World native arts, especially as Europe was plunging back into war; Roland J. McKinney was quoted as saying "If Europe blows up and destroys its cultural heritage, the Americas can turn for inspiration to their own, indigenous art, the art that predates Columbus." The imagery is a comprehensive marriage of the themes of Mexican artistry and US technology in Pan-American Unity.

The mural included the images of his wife, Frida Kahlo, woodcarver Dudley C. Carter, and himself, planting a tree and holding the hand of actress Paulette Goddard. Timothy L. Pflueger is depicted holding the architectural plans for the planned Pflueger Library.

The mural is composed of ten panels arranged in five sections, all of which relate Rivera's firmly held belief that multicultural artistic expression will form into a unified cultural entity regardless of individual points of origin. His belief in the eventual unity of the Americas, which became a common thread in much of his non-artistic expression, inspired the images represented in this mural.

Each section consists of a larger upper panel and a smaller lower panel. The sections are numbered from left to right.

'The Creative Genius of the South Growing from Religious Fervor and a Native Talent for Plastic Expression'

Persons depicted in Section One include:

'Elements from Past and Present'

Persons depicted in Section Two include:

'The Plastification of Creative Power of the Northern Mechanism by Union with the Plastic Tradition of the South'

The central section is largely taken up by a depiction of Coatlicue, Aztec Goddess of Life, merged with a huge stamping machine from Detroit, symbolizing the union between north and south. It is echoed throughout the section in the depiction of the modern carver (Carter) eschewing motorized tools for hand axes, in Kahlo looking for inspiration in native traditions (and dressed in native clothes), and in the symbolic joining of Rivera (from Mexico) and Goddard (from America) holding the "Tree of Life and Love" together.

Persons depicted in Section Three include:

'Trends of Creative Effort in the United States and the Rise of Woman in Various Fields of Creative Endeavor through Her Use of the Power of Manmade Machinery'

Persons depicted in Section Four include:

'The Creative Culture of North Developing from the Necessity of Making Life Possible in a New and Empty Land'

Persons depicted in Section Five include:

In the past, people have asserted that Diego's paintings predominantly feature allegorical, figurative figures that potentially conform to societal and historical attributes assigned to women, which would be evidence of the male gaze in his artistic creations. However, women are not simply objectified in the mural, which features a diverse array of figures that symbolize the cultural amalgamation of the Americas. The poses of the female figures vary, encompassing roles that span from agricultural labor to intellectual pursuits, suggesting a deliberate effort to depict women in diverse and empowered roles. However, some figures exhibit traditional femininity, raising questions about whether Rivera fully subverts established gender roles. The direction that the female figures are looking varies — some meet the viewer’s gaze with confidence, while others are engrossed in their activities, creating a nuanced interplay between agency and objectification.

During the completion of the mural in November 1940, the editorial board of the Madera Times opined "There will be many who view the work who will wonder why, after it is placed in storage, it is not permitted to remain there. There would be no great loss to the art world if this could happen."

Patrick Marnham wrote "The colours and many of the details are superb ... Yet there is something unconvincing about the political ideas expressed" in his 1998 biography of Rivera. ... it would have made a wonderful storyboard for a Hollywood feature cartoon — but it does not move us." By 2021, Neal Benezra declared it "Rivera's painterly plea for a kind of unity of the Americas ... an anti-nationalist way of looking at things."

Pan American Unity inspired a poem by Bob Hicok, "Rivera's Golden Gate Mural", published in his first collection of poetry, The Legend of Light.

From June 2021 to 2023, the mural will be exhibited at the San Francisco Museum of Modern Art (SFMoMA) and complement the exhibition, Diego Rivera's America, to open in 2022. It will be in the Roberts Family Gallery, which is freely accessible to the public. It will be returned to the college in 2023.

• City College of San Francisco
• List of works by Diego Rivera

• The Diego Rivera Mural Project at CCSF
• The Diego Rivera Mural Project website
• Silent Movie of Diego Rivera and his team painting the Pan American Unity mural at GGIE
• Kost, Ryan (10 January 2016). "The delicate art of moving, photographing Diego Rivera mural". San Francisco Chronicle. Retrieved 10 July 2017.