In a discharge lamp ignition apparatus, a control circuit unit: lowers a drive frequency from a predetermined initial frequency; establishing, if a resonant voltage reaches an ignition voltage for igniting a discharge lamp, a drive frequency at the ignition voltage as a discharge-lamp-ignition drive frequency which is a frequency for igniting the discharge lamp; and sets, if the resonant voltage does not reach the ignition voltage even though the drive frequency is lowered from the predetermined initial frequency to a resonant frequency, a frequency which is a predetermined value higher than the drive frequency at a resonant voltage peak voltage as the discharge-lamp-ignition drive frequency, and an inverter circuit unit alternating-current drives the resonant circuit unit at the discharge-lamp-ignition drive frequency established by the control circuit unit.