PT Telekomunikasi Selular (trading as Telkomsel) is an Indonesian wireless network provider founded in 1995 and is owned by Telkom Indonesia (65%) and Singtel (35%). It is headquartered in South Jakarta.

Telkomsel is the largest cellular telecommunication carrier in the country with a 169.5 million customer base as of 2020. The company operates its GSM network on the 900–1800 MHz frequency range, as well as 3G, 4G, and 5G services on other frequencies. Telkomsel operates a variety of mobile services, chief among them are Telkomsel PraBayar (a consolidation of simPATI, card As, and LOOP, all of them Telkomsel's prepaid services) and Telkomsel Halo (formerly kartuHalo). These brands differ in their payment model (prepaid vs. postpaid) as well as pricing. As of the first quarter of 2020, Telkomsel had a 66.4% share of the Indonesian mobile phone market.