Born and raised in the city of Nara, Takaichi graduated from to Nara Prefectural Unebi Senior High School for her secondary education, then she received Bachelor of Business Administration from Kobe University in 1984.
She graduated from Matsushita Institute of Government and Management. In 1987, she moved to the United States to work for Democratic U.S. Representative Patricia Schroeder as a Congressional Fellow. When Takaichi returned to Japan on 1989, she gained attention from the mass media as a legislative analyst with experience in the US Congress, and wrote books based on the experience. In 1992, she formed Kansai Hi-Vision Consortium and presided as the first chairperson.
In 1993, Takaichi ran as an independent candidate for the House of Representatives of Japan, Nara Prefectural district and won the most votes. She joined the "Liberals" study group of Liberal Democratic Party (LDP), led by Koji Kakizawa, which became part of the New Frontier Party.
In 1996, Takaichi ran as sanctioned candidate from New Frontier Party and reelected to the House of Representatives (lower house). However New Frontier Party lost nationally. On November 5, she responded to recruitment from the Secretary-General of LDP Koichi Kato, and, then, joined the LDP. Act of switching the party, two months after winning the election with anti-LDP votes resulted in heavy criticism from the New Frontier Party members.
In the LDP, Takaichi belonged to the Mori Faction (formally, the Seiwa Seisaku Kenkyū-kai) and she served as a Parliamentary Vice Minister for the Ministry of International Trade and Industry under Keizō Obuchi cabinet. She also served as chairman of Education and Science Committee. In 2000, House of Representatives election she was placed in the first position in proportional representation ballot from LDP and easily won her third term. In 2002 she was appointed as the Senior Vice Minister of the Ministry of Economy, Trade and Industry under Junichiro Koizumi.
However, in 2003 lower house election, the first since she switched parties with her own name on the ballot, she lost. In 2004 she took a faculty position at Kinki University. She married Taku Yamamoto who is a fellow member of the House of Representatives.
Takaichi served as Minister of State for Okinawa and Northern Territories Affairs, Minister of State for Science and Technology Policy, Minister of State for Innovation, Minister of State for Youth Affairs and Gender Equality and Minister of State for Food Safety in the Japanese Cabinet of Prime Minister Shinzō Abe.
On September 3, 2014, Takaichi is selected as Minister of Internal Affairs and Communications to replace Yoshitaka Shindō.
Like most members of Abe's Cabinet, and the Prime Minister himself, Takaichi is affiliated to the openly revisionist organization Nippon Kaigi.
As soon as she was named as cabinet minister, a couple of embarrassing stories resurfaced in the international press:A picture of her together with Kazunari Yamada, the leader of Japan's Neo-Nazi party, in front of Japanese national flag (LDP leader Tomomi Inada also appeared on similar pictures). She denied any link with him and said she wouldn't have accepted the picture had she known Yamada's background.
In 1994, she was shown promoting a controversial book praising Adolf Hitler's electoral talents.
A few weeks later, Takaichi was among the three members of the cabinet to visit the controversial Yasukuni shrine.
On February 9, 2016, the extreme right wing Internal Affairs and Communications Minister Sanae Takaichi said Tuesday that broadcast stations could be ordered to cease operations in the event they repeatedly present politically biased broadcasts in violation of the country’s domestic law severely restricting journalistic freedom.