A damning inspection report published in September 2014 criticised high caseloads and warned that as many as 500 children were at risk due to delays in carrying out assessments.
However inspectors conducting a fresh inspection over four weeks in October and November found "good evidence of improvement across all services areas".
"Strong leadership, an ambitious and well-articulated vision, ‘Our Manchester, our children' and robust governance arrangements are leading to improved outcomes for children and young people in need of help and protection, for children in care and for care leavers," the report states.
"The pace of change has accelerated in the last 18 months since the appointment of the current director of children's services and his senior management team.
"They, together with the chief executive, have been instrumental in driving the transformation plan."
Ofsted said senior leaders were found to be "energetic, active and visible", creating an environment in which good-quality social work is increasingly evident.
Successful workforce planning and development were found to have resulted in the recruitment of 40 per cent more frontline social workers to the locality and permanence teams, reducing the average number of cases allocated to each social worker.
Sheila Newman, lead member for children's services for Manchester City Council, said: "We are very pleased that Ofsted have seen clear evidence of improvements since the last inspection and the positive difference that is being made to lives of Manchester children.
"This endorsement is the result of commitment, focus and sheer hard work by everyone involved in this process - from senior officers and members to frontline staff.
"This inspection result is a cause for satisfaction but not celebration. This is not the end of our improvement journey and there is absolutely no room for complacency.
"'Requires improvement' means exactly that. We said at the time of the last inspection that we would not rest until services were rated 'good' and we remain firmly fixed on that goal.
"We are making clear progress but we are determined to keep improving to ensure we are delivering the best possible services for our young people. We know what we need to get there, have plans in place and our focus now is pressing on with them."