The biggest strike for five years closed thousands of schools and disrupted courts, driving tests and jobcentres, with warnings of fresh industrial action to come.
Hundreds of thousands of teachers, lecturers, civil servants and other workers walked out in protest at controversial changes to their pensions, which they attacked as "unfair and unjust".
Unions clashed with the Government over the impact of the strike, while Labour leader Ed Miliband was told he was a "disgrace" for failing to support the action.
Mark Serwotka, leader of the Public and Commercial Services (PCS) union, predicted that up to four million workers could be involved in strikes in the autumn if the bitter row is not resolved.
PCS members will start a month-long ban on overtime from midnight, which Mr Serwotka said would hit work in jobcentres, passport and benefit offices and Government departments.
The PCS said it was the best supported strike it had ever held, with 200,000 taking action, but the Government put the figure at half that, saying action was "premature" while negotiations were continuing.
More than 11,000 schools in England alone were disrupted due to the walkout, according to the Department for Education. Teaching unions suggested the numbers were higher, with the Association of Teachers and Lecturers saying that around 85% of schools were fully or partially closed across England and Wales.
Mr Miliband criticised workers for walking out while negotiations on reform of their pensions were still ongoing, saying that while he understood the anger of the teachers and civil servants involved, the action was "wrong" and would not help them win their argument with the Government. Mr Miliband later said that the strike had been "a mistake" which would not help unions win the fight for public support.
There was strong criticism of the Labour leader at a union rally in London where one speaker branded his stance a "disgrace" to loud cheers from the audience. Unions said up to 20,000 took part in a huge march and rally in central London, which passed Downing street and Parliament, before a series of speakers lined up to warn that cutting pensions would force people to leave teaching or quit pension schemes.
Figures gathered from Government departments showed that - as of 4.30pm - some 105,890 civil servants had taken part in the strike, said the Cabinet Office. In a statement, the Cabinet Office said that just 42% of PCS members stayed away, while other members of the union turned up to work. The "vast majority" - around 80% - of the civil service workforce was not on strike and fewer PCS members joined the industrial action than in earlier disputes in 2004 and 2007, said the statement.