The report by professional services firm PwC found sustainable and well regulated growth could create 218,000 jobs across the UK and 47,000 jobs in the financial services sector.
The report "Where next? Assessing the current and future contribution of the UK Financial Services sector also predicted robust regulation would lead to GDP growth of 2-3% by 2020.
"A well-functioning financial services sector improves both capital efficiency and overall UK productivity," said PwC director and financial services economist Nick Forrest.
"Business confidence depends upon trust in a well functioning financial services sector.
"The greater confidence that businesses have that their future profitability will increase, the more likely it is that they will invest, leading to an increases in the different components of GDP such as consumption and exports."
In an alternative scenario, in which the financial services sector continues to languish and a regulatory environment that "does less to facilitate growth, UK GDP could rise by just 0.2% and create only 12,000 jobs, in the period to 2020.
Kevin Burrowes, UK financial services leader at PwC, said: "While limiting the likelihood and impact of future crises must be a top priority, better regulation does not necessarily mean more regulation.
"The UK needs some re-balancing of financial services regulation to unlock the industry's potential in a sustainable and stable way to achieve the contribution that financial services can clearly give to the economy."
The report found the region benefiting most from this level of job creation would be London, with 132,800 new jobs by 2020. The region to benefit least would be Northern Ireland creating only 2,900 new jobs.
