The invention provides an electrostatic charge image developing toner, an electrostatic charge image developer, and a toner cartridge. The electrostatic charge image developing toner includes: a tonerparticle having average circularity of 0.91 or more and 0.98 or less, a silica particle externally added to the toner particle, and a strontium titanate particle that is externally added to the tonerparticle, that has an average primary particle diameter of 10 nm or more and 100 nm or less, that has average primary particle circularity of 0.82 or more and 0.94 or less, and circularity that becomes 84% of accumulation of the primary particle of more than 0.92.