The former Celtic striker delivered an apparently unprovoked blow to Jon Jönsson’s stomach. The punch floored the Elfsborg player, although the referee missed the incident.
The ban means that Larsson will miss Helsingborg’s match against Gais and the Skåne derby against Malmö FF.
The Swedish Football Association’s competition committee announced the punishment at Friday lunchtime.
“Larsson’s actions were not connected to the game and cannot be seen as an unintentional reflex,” the committee wrote in its ruling.
Expressen quotes Bosse Andersson, an official at Helsingborg, saying that the club was “inclined to appeal” the ban.