Janice Kelly told the Hutton inquiry on Monday that her late husband had felt totally let down and betrayed.
When asked for more detail by Lord Hutton, she added: "I believed he meant the Ministry of Defence because they were the ones who had effectively let his name be known in the public domain."
His widow said Kelly had received assurances from his line manager and senior ministry officials that his name would not be made public.
"I'd never known him to be as unhappy as he was then" [before his committee appearance], Janice Kelly said via videolink to the Hutton inquiry.
Kelly killed himself on 15 July a few days after he was grilled in public by a parliamentary committee, following his exposure as the source of a BBC report accusing the government of exaggerating the threat of Iraqi weapons of mass destruction.
A statement issued by the family after his body was discovered in woodlands close to their home in Oxfordshire, said his life had been made "intolerable".
David Kelly’s daughter, Rachel, is also listed to testify on Monday, along with friends of the scientist and other family members.
Kelly said in an article he wrote just before the invasion of Iraq that there was no imminent danger, and the threat of danger was only "modest".
Lord Hutton heard Janice Kelly's
evidence by videolink
The British Observer newspaper quoted Kelly as writing: "War may now be inevitable. The proportionality and intensity of the conflict will depend on whether regime change or disarmament is the true objective."
Kelly's neighbour, Ruth Absalom and his friend, the journalist Tom Mangold, are also due to give evidence to the inquiry later in the week.
Offer of support
Mangold had guessed Kelly was the BBC's source and sent an email to the quietly spoken scientist, a week before he committed suicide.
"I am available for help, consultation, a drink, a dry shoulder or whatever. Kelly simply replied: "Thanks. Not a good time to be in communication."
Other witnesses this week include Dr Nicholas Hunt, who performed the post mortem, Michael Page, the assistant chief constable of Thames Valley Police, and those involved in recovering Kelly's body.
Personnel from the defence intelligence staff will also be called on Wednesday.
A spokesman for the inquiry said there might be two such witnesses, but their names were not being released.