PT Semen Indonesia (Persero) Tbk (SIG) (Indonesian: CUM) is a state-owned holding company providing building material solutions. The company has 17 subsidiaries located in Indonesia and Vietnam. With a market reach to Asia, Australia and Oceania, the company's main business is in the cement sector and its derivative products such as concrete, mortar, precast, and aggregate.

In running its main business process, the company has supporting business lines such as construction and manufacturing services, land and sea transportation services, industrial packaging provider, mining services, international trade service, and building material solution applications. In addition, through several subsidiaries and business units, the company also does business in property, industrial estate management, industrial waste management, informatics solutions, and health services.

The company began its history in 1953, when the Indonesian Government established the legal entity N.V. Pabrik Semen Gresik with an installed capacity of 250,000 tons of cement per year. In 1957, President Sukarno inaugurated the company's cement plant. In 1961, the government changed the company's legal entity into a state-owned company under the name PN Semen Gresik. In 1969, on various considerations, the company's legal entity status was changed to a limited liability company.

In 1991, the company was officially listed on the Jakarta Stock Exchange and Surabaya Stock Exchange. At that time, the installed capacity of the company had reached 1.8 million tons of cement per year. In 1995, the company acquired PT Semen Padang and PT Semen Tonasa, bringing its installed capacity to 8.5 million tons of cement per year. In 1998, CEMEX officially held 14% of the company's shares, which was increased to 25.5% a year later. In 2006, Blue Valley Holdings purchased 24.9% of the company's shares held by CEMEX, and sold them four years later.

In 2012, the company acquired Thang Long Cement Joint Stock Company in Vietnam, which had an installed capacity of 2.3 million tons of cement per year at the time. In 2013, the company transformed into a strategic holding company and changed its name to what it is today, and separated its cement production business to PT Semen Gresik.

In 2019, through Semen Indonesia Industri Bangunan, the company acquired 80.64% of PT Holcim Indonesia Tbk shares owned by Holderfin B.V. and then changed the name from PT Holcim Indonesia Tbk to PT Solusi Bangun Indonesia Tbk. Holcim's product brand was also changed to Dynamix. In 2020, the company changed its trade name and logo from Semen Indonesia to SIG, emphasizing the company's vision as a building material solutions provider. In 2021, SIG entered into a strategic partnership with Taiheiyo Cement Corporation which officially holds 15.04% shares of Solusi Bangun Indonesia. In 2022, as a part of SOE cement subcluster integration, the Government of Indonesia transferred the ownership of shares in PT Semen Baturaja Tbk to SIG, making it officially part of SIG.

A wide selection of bagged green cement brands supported by 385 distributors and more than 70,000 retail stores across Indonesia.

Environmentally friendly multi purpose cement for general construction, housing, and concrete block wall panel applications.