Named after Gidea Hall, a manor house first recorded in the mid-13th century.
The Victoria County History gives the form Gidiehulle in 1250–1 and calls the name obscure. Wikipedia and Londonist link it to 'Geddy Hall', said to come from ged, pike, and ea, water. In 1910 Gidea Park Ltd began a garden suburb on the estate; the station opened that year as Squirrels Heath & Gidea Park and dropped 'Squirrels Heath' in 1969.