Dublin Fire Brigade says five different fires in Bushy Park last night may have been started maliciously.
The first one began at around 9 o'clock and the last was dealt with at 10.15pm.
Fire crews say Gardai assisted Rathfarnham firefighters at the scene in Terenure.
DFB also dealt with early morning gorse fires in Ticknock, Citywest and Glencullen.
A spokesperson has told 98FM News they're asking "people to remain fire vigilant during this drought and report suspicuous activity to the gardai. Parents should warn their children, teenagers and young adults about the dangers of lighting fires in grassy and wooded areas."