Spying for other countries or groups is in many cases illegal and punishable by law. The following is a list of individuals that have either been imprisoned for spying, or individuals that have been arrested in connection to their spying activities.
| Name | Nationality | Summary | Conviction Date | Penalty | |
|---|---|---|---|---|---|
| American | Convicted of spying for the Soviet Union and Russia | Life sentence (without parole) | |||
| American | Sold secret documents to the Soviet Union and is estimated to have received $60,000 from the KGB | 24 Years and 4 Months | |||
| Belgian | Life sentence (released 2 years later) | ||||
| Clayton J. Lonetree | American | Convicted for providing classified information to the Soviet Union while stationed in Moscow as a guard at the U.S. Embassy | August 21, 1987 | 30-year sentence, reduced to 15, released February 1996 | |
| Alexander Fishenko | American-Russian | Convicted for illegally exporting microelectronics from the U.S.A. to Russia | July 21, 2016 | 10-year sentence[1] | |
| American | Signals analyst who sold eavesdropping and code secrets to East Germany and the Soviet Union from 1983 to 1988 | 40-year sentence | |||
| American | Spied for Soviet and Russian intelligence services against the United States from 1979 to 2001 | Life sentence (without parole) | |||
| American | Convicted for conspiracy to commit espionage for the government of Cuba | 25-year prison term followed by five years probation | |||
| American | Twice-convicted spy for Russia's Foreign Intelligence Service | 23 years 7-month sentence | |||
| American | Convicted for attempted espionage and fraud against the United States for the government of Israel | 13-year sentence | |||
| American | Spied for and sold secret documents to the Soviet Union. Was known to have a photographic memory and as such never passed any physical documents on. | Life sentence (Released November 24, 2015) | |||
| American | Accused of spying for the Soviet Union and Russia, and pleaded guilty to conspiring and attempting to commit espionage | 27-year sentence | |||
| American | Passed classified information to Israel while working as an American civilian intelligence analyst | Life sentence (Released November 20, 2015) | |||
| American | Convicted for spying for the Soviet Union during the 1970s and 1980s | Life sentence | |||
| American | Convicted of spying for the Soviet Union from 1968 to 1985 | Life sentence | |||
| Brian Patrick Regan | American | Convicted of one of gathering national defense information and two counts of attempted espionage for soliciting classified information to Iraq, China, and Libya. | March 21, 2003 | Life sentence | |
| Chelsea Manning | American | Convicted of six counts of the espionage act for providing classified information to Wikileaks | July 30, 2013 | 35-year sentence, commuted (released May 17, 2017) | |
| Dongfan "Greg" Chung | Chinese | Convicted of economic espionage; stole trade secrets related to the US Space Shuttle program and the Delta IV rocket and provided them to China | July 16, 2009[2] | 15-year sentence, died May 18, 2020, while incarcerated[3] | |
| Kendall & Gwendolyn Myers | American | Convicted of spying for Cuba across a 30-year span | November 20, 2009 | Life sentence (without parole); 81 months |