The figure was announced by the First Minister Carwyn Jones at the today (5 December).
The report, which spans a ten-year period between 2006 and 2016, was carried out by Econactive for the Welsh Rugby Union (WRU). The consultancy's last report in 2007 found the stadium then delivered £100m a year for the Welsh economy.
It also found 70% of the visitor spend at the Millennium Stadium was non-local in origin. The venue attracts 770,000 paying visitors each year to main events such as international rugby and rock music concerts.
Econactive revealed visitor numbers are expected to increase with Heineken Cup Finals in 2014 and 2016, along with eight Rugby World Cup games in 2015.
Jones said: "This thought provoking report reiterates the importance of major events to the economic development and regeneration of host cities and regions and demonstrates the part played by the Millennium Stadium in achieving this.
"The stadium is a key component of what Wales has to offer as a host of major events. The stadium has set its sights on attracting high profile events of global importance which have attracted more visitors from outside Wales."
Roger Lewis, WRU's group chief executive, said: "This report confirms the huge value of the Millennium Stadium to the wider economy and to Wales. Major events at the stadium are invariably seen around the world on television screens and the people who travel to Wales to watch make an important impact on the Welsh economy.
"We commissioned this report to show the significance of the stadium and the activities of the Welsh Rugby Union to Wales and we are determined to work hard to ensure we sustain the level of activity that delivers this long term benefit to us all."
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