Albert Ghiorso (July 15, 1915 – December 26, 2010) was an American nuclear scientist and co-discoverer of a record 12 chemical elements on the periodic table. His research career spanned six decades, from the early 1940s to the late 1990s.

Ghiorso was born in Vallejo, California on July 15, 1915, of Italian and Spanish ancestry. He grew up in Alameda, California. Living near the Oakland International Airport, he became interested in airplanes, aeronautics, and other technologies. After graduating from high school, he built radio circuitry and earned a reputation for establishing radio contacts at distances that outdid the military.

He received his BS in electrical engineering from the University of California, Berkeley in 1937. After graduation, he worked for Reginald Tibbets, a prominent amateur radio operator who operated a business supplying radiation detectors to the government. Ghiorso's ability to develop and produce these instruments, as well as a variety of electronic tasks, brought him into contact with the nuclear scientists at the University of California Radiation Laboratory at Berkeley, in particular Glenn Seaborg. During a job in which he was to install an intercom at the lab, he met two secretaries, one of whom, Helen Griggs, married Seaborg. The other, Wilma Belt, became Albert's wife of 60+ years.

Ghiorso was raised in a devout Christian family, but later left the religion and became an atheist. However, he still identified with Christian ethics.

In the early 1940s, Seaborg moved to Chicago to work on the Manhattan Project. He invited Ghiorso to join him, and for the next four years Ghiorso developed sensitive instruments for detecting the radiation associated with nuclear decay, including spontaneous fission. One of Ghiorso's breakthrough instruments was a 48-channel pulse height analyzer, which enabled him to identify the energy, and therefore the source, of the radiation. During this time they discovered two new elements (95, americium and 96, curium), although publication was withheld until after the war.

After the war, Seaborg and Ghiorso returned to Berkeley, where they and colleagues used the 60" Crocker cyclotron to produce elements of increasing atomic number by bombarding exotic targets with helium ions. In experiments during 1949–1950, they produced and identified elements 97 (berkelium) and 98 (californium). In 1953, in a collaboration with Argonne Lab, Ghiorso and collaborators sought and found elements 99 (einsteinium) and 100 (fermium), identified by their characteristic radiation in dust collected by airplanes from the first thermonuclear explosion (the Mike test). In 1955, the group used the cyclotron to produce 17 atoms of element 101 (mendelevium), the first new element to be discovered atom-by-atom. The recoil technique invented by Ghiorso was crucial to obtaining an identifiable signal from individual atoms of the new element.

In the mid-1950s it became clear that to extend the periodic chart any further, a new accelerator would be needed, and the Berkeley Heavy Ion Linear Accelerator (HILAC) was built, with Ghiorso in charge. That machine was used in the discovery of elements 102–106 (102, nobelium; 103, lawrencium; 104, rutherfordium; 105, dubnium and 106, seaborgium), each produced and identified on the basis of only a few atoms. The discovery of each successive element was made possible by the development of innovative techniques in robotic target handling, fast chemistry, efficient radiation detectors, and computer data processing. The 1972 upgrade of the HILAC to the superHILAC provided higher intensity ion beams, which was crucial to producing enough new atoms to enable detection of element 106.

With increasing atomic number, the experimental difficulties of producing and identifying a new element increase significantly. In the 1970s and 1980s, resources for new element research at Berkeley were diminishing, but the GSI laboratory at Darmstadt, Germany, under the leadership of Peter Armbruster and with considerable resources, was able to produce and identify elements 107–109 (107, bohrium; 108, hassium and 109, meitnerium). In the early 1990s, the Berkeley and Darmstadt groups made a collaborative attempt to create element 110. Experiments at Berkeley were unsuccessful, but eventually elements 110–112 (110, darmstadtium; 111, roentgenium and 112, copernicium) were identified at the Darmstadt laboratory. Subsequent work at the JINR laboratory at Dubna, led by Yuri Oganessian and a Russian-American team of scientists, was successful in identifying elements 113–118 (113, nihonium; 114, flerovium; 115, moscovium; 116, livermorium; 117, tennessine and 118, oganesson), thereby completing the Period 7 elements of the periodic table of the elements.