Arnaldo Pomodoro (23 June 1926 – 22 June 2025) was an Italian sculptor based in Milan. His signature works are Sphere Within Sphere (Sfera con Sfera), bronze spheres with smooth exterior and broken interiors. They are displayed in public spaces such as the United Nations Headquarters, the University of California, Berkeley, Trinity College Dublin, the Hirshhorn Museum and Sculpture Garden in Washington, D.C., Tel Aviv University in Israel and at the Vatican Museums.

Arnaldo Pomodoro was born in Morciano, Romagna, in the Montefeltro area, on 23 June 1926. His father worked in various jobs and also wrote poetry; his mother worked as a dressmaker. He would have liked to become an architect or a scenic designer, but received a diploma from the Technical Institute for Surveyors in Rimini and also trained there as a goldsmith. He worked at the public works office in Pesaro as an advisor for the restoration of historic buildings damaged in World War II, and as a goldsmith. He attended the Art Institute in Rimini to study scenic design.

In 1953, Pomodoro attended an exhibition of Picasso which was held in Milan at the Palazzo Reale, showing Guernica. It made a strong impression on him, and a year later he moved to Milan where he joined the artistic community and became friends with Lucio Fontana, Dangelo, Sanesi, Enrico Baj, and others. He experimented with objects in jewelry-style, with overlays in silver and gold. His artworks were first presented at the Galleria Numero of Florence and Galleria Montenapoleone of Milan. In 1955, his first sculpture was exhibited at Galleria del Naviglio of Milan. He took part in the 10th Triennale in Milan, and together with his brother Giò he also participated in the 1956 Venice Biennale, earning him his first international recognition.

Pomodoro received a grant to study American art, and traveled to the United States in 1959. He described his visit to MoMA and seeing Brancusi's sculptures as a strong inspiration for his work. In San Francisco, he met Mark Rothko who was teaching at the California School of Fine Arts. In New York, Pomodoro met Costantino Nivola and Enrico Donati who introduced him to such artists as Franz Kline, Jasper Johns, Andy Warhol, and others. He also met sculptors David Smith and Louise Nevelson, and organized an exhibition New Work from Italy, dedicated to Italian artists.

In the 1960s, Pomodoro began to create larger pieces in geometric shapes such as cubes and triangles. Some reviewers saw them as buildings stripped of facades by bombings. He developed a collaboration with the Marlborough Gallery in New York. In 1963, Pomodoro received the International Prize for Sculpture at the VII São Paulo Biennale and also the National Prize for Sculpture at the XXXII Venice Biennale in 1964. Pomodoro arrived at spheres covered partly with a polished bronze; the Museum of Modern Art bought his Sphere, I in 1964. In 1966, he became an artist in residence at Stanford University, and then at UC Berkeley and Mills College. He created the Sfera grande for the Italian Pavilion at the 1967 Montreal Expo, beginning his project of monumental spheres. This sculpture is now located in front of the Farnesina Palace in Rome. He was awarded the International Prize for Sculpture from the Carnegie Institute in Pittsburgh in 1967.

In 1972, Arnaldo Pomodoro returned to set design, and worked on Kleist's play Das Käthchen von Heilbronn staged in Zurich. In 1984, he had a large retrospective exhibition at the Forte di Belvedere in Florence. In 1988, Pomodoro participated in the Venice Biennale as well as the international exhibition of sculpture at the World Expo in Brisbane. His work Forme del Mito (Forms of Myth) which was displayed at the Expo, was later purchased by Brisbane City Council for the City of Brisbane.

In 1990, Pomodoro received the Praemium Imperiale for Sculpture from the Japan Art Association. His work Sfera con Sfera was installed in the Cortile della Pigna of the Vatican Museums. Works of this title became his recognisable signature works, massive bronze spheres with a shiny and smooth exterior and broken interiors that he compared to a superficial perfection of exteriors and the troubled complexity of interiors. The Vatican sphere features a mechanism responding to the wind. In 1992, he was awarded an honorary doctorate by Trinity College in Dublin when a Sfera con Sfera was installed. The following year he was nominated the honorary member of the Brera Academy in Milan.

In 1995, the Fondazione Arnaldo Pomodoro was created as a cultural and exhibition center dedicated to contemporary art. Originally conceived as a centre to document and archive the work of the artist, it opened an exhibition space in 2005, hosting exhibitions of prominent artists such as Jannis Kounellis, Lucio Fontana, and Robert Rauschenberg.