Järfälla adopted its coat-of-arms in 1955. The design, based on a seal from 1568, represents the Lamb of God bearing an archbishop’s cross. Of the parishes that together with Järfälla comprised the ancient Sollentuna district, only Järfälla and Sollentuna remain as independent municipal entities, and Sollentuna has adopted a different coat-of-arms. 

From the 1670s up until 1905, the site of the district court was in Järfälla. In other words, it was here that the district seal was used on various documents that were expedited by the court.