The acquittal followed a seven-week trial that focused on Espy's attendance at parties and sporting events while he was President Clinton's first agriculture chief in 1993 and 1994.
Espy had faced 30 counts covering about $33,000 worth of gifts and entertainment. U.S. District Judge Ricardo Urbina had thrown out an additional eight charges before the jury began its deliberations.
The jury deliberated nine hours over two days before finding Espy innocent of all 30 counts.
The accusations included three charges that Espy had violated a 90-year-old federal law banning gifts to meat inspectors that would have carried a minimum sentence of one year each if he had been convicted.
Espy, 45, pleaded innocent, and has always maintained that he did nothing wrong by accepting favors from chicken producer Tyson Foods Inc. and other firms.
He and his lawyers hugged when the jury forewoman read the verdict. Family members and supporters in the front rows of the courtroom gasped and began crying.
Independent Counsel Donald Smaltz, who spent more than four years and $17 million prosecuting Espy, his associates and businesses that gave him gifts, had no visible reaction in the courtroom.
Smaltz claimed that Espy had his hand out from his first night on the job, when Tyson gave him extra tickets to an Inaugural dinner for Clinton.
Other charges involved trips Espy took to the 1994 Super Bowl, a Chicago Bulls playoff game and the U.S. Open tennis tournament.
In some cases, Espy sought out the tickets or made no attempt to conceal the fact that a company he regulated was paying the bills. In other cases, Espy never knew who was paying the bills, or believed the favors were fine under federal gift laws, witnesses testified.
Federal ethics laws forbid expensive gifts to officials such as Espy, but make some exceptions for presents between established friends. Espy claimed many of the gifts fell under that exception.
The secretary was forced to resign in 1994 after the White House became concerned with the continuing revelations about his off-hours socializing with farm company executives.
Espy was the first Cabinet-level official to face trial since Raymond Donovan, labor secretary under Ronald Reagan. Donovan was acquitted in 1987 on charges involving old business deals.
Former Clinton Housing and Urban Development Secretary Henry Cisneros faces trial in February on charges involving payments he made to an ex-lover.
Espy was a Democratic congressman from Mississippi when Clinton picked him for the Cabinet. Thus he was already familiar with federal ethics requirements, Smaltz argued during the trial.
Espy's lawyers did not put on any witnesses, leaving the jurto decide guilt or innocence only on the strength of Smaltz's case.
The trial is the culmination of Smaltz's multifaceted prosecution, which won convictions or guilty pleas involving some companies and lobbyists who gave things to Espy.
Smaltz also lost several other important cases, including his attempt to prosecute Espy's brother, Henry, for campaign violations. Henry Espy made an unsuccessful run for Congress in 1993, hoping to fill the seat Mike Espy vacated when he became a Cabinet secretary.
Mike Espy returned to his home state after leaving Washington. He has a law office in Jackson.