Federal prosecutors announced the charges as they listed a catalogue of alleged abuses.
The Justice Department has been scrutinising Baltimore police after accusing it last August of systemic racism and abusing power.
The officers "arrogantly" ignored clear directives, a police official said.
Police Commissioner Kevin Davis condemned the officers at a news conference.
"These officers are 1930s-style gangsters," Mr Davis said. "They betrayed the trust we're trying to build with our community at a very sensitive time in our history."
The seven officers are: Momodu Gondo, Evodio Hendrix, Daniel Hersl, Sergeant Wayne Jenkins, Jemell Rayam, Marcus Taylor and Maurice Ward.
Mr Gondo is also charged with participating in a drug conspiracy.
All of the men were arrested, suspended without pay and jailed, pending detention hearings on Thursday.
Federal prosecutors said the men began their criminal enterprise in 2015, after the city erupted into protest over the death of a young black man, Freddie Gray, while he was in police custody.
The Justice Department later opened a "pattern and practice" investigation into the police force, finding that the department routinely discriminated against black people and used excessive force.
Federal agents by then had spent months following officers on the Gun Trace Task Force, which was formed to crack down on violent crime by tracking illegal guns on the streets.
Prosecutors accuse the men of committing robberies and filing false reports to conceal their crimes.
In one instance, four of the officers arrested a man during a traffic stop and confiscated drugs as well as $21,500 (Â£17,516).
The officers only submitted $15,000 as evidence, and then later went to the man's home and stole $200,000 and a $4,000 watch from a safe deposit box.
In another incident, three of the officers stopped a man on the street, searched his car without a warrant and later took $1,500 he had earned working as a maintenance supervisor at a nursing home.
The charges were announced a day after US Attorney General Jeff Sessions suggested that he might ease federal scrutiny of law enforcement across the country as it could undermine their policing ability.
Baltimore was one of dozens of US cities to face a federal civil rights probe under the Obama administration.
The city and the Justice Department had reached a court-enforceable consent decree in January requiring police to make sweeping changes to its practices.
Mr Obama made police reform a priority in the wake of mounting racial tension and high-profile police shootings across the country.
Baltimore police union president Gene Ryan said he was "disturbed" by the recent charges.
DeRay Mckesson, a local Black Lives Matter activist, said the charges were disturbing but signalled reform.
"It is promising to see the beginning of accountability being applied to the Baltimore Police Department," he said.
"The indictments confirm what activists and community members have been saying for decades."

The group sparked outrage in the western city of Wuppertal in 2014, when they approached people in orange vests bearing the words "Sharia Police".
They demanded that locals stop gambling, listening to music, and drinking alcohol.
The group's alleged organiser, Sven Lau, is a well-known Islamist preacher.
He is facing separate charges of supporting a terrorist group fighting in Syria.
A film of the "patrol" appeared on YouTube, prompting condemnation from the Central Council of Muslims in Germany, who said their behaviour was "harmful to Muslims".
Wuppertal's district court ruled that the seven vigilantes could only have broken the law - which was originally aimed at street movements such as the early Nazi party - if their uniforms were "suggestively militant or intimidating", a court spokesman said.
In this case, it found that the vests were not threatening, noting that one witness mistook the gang for a stag do.
The same court threw out the case last year, but was overruled on appeal by a higher court which felt the ban on uniforms could be applied in this case.
Monday's verdict is not yet final and may still be appealed.
So-called "Sharia patrols" by ultra-conservative Muslim men have been seen in other European cities including London, Copenhagen and Hamburg.
Seven Baltimore police officers have been charged with robbery, extortion, falsely detaining people and faking reports to cover it up.
[NEXT_CONCEPT]
A German court has ruled that seven Muslim men who formed a Sharia street patrol did not break laws against political uniforms.