Seiko Hashimoto (橋本 聖子, married name: Seiko Ishizaki (石崎 聖子), born October 5, 1964 in Hayakita, Hokkaido) is a former ice speed skater and track cycling sprinter from Japan, who represented her native country in four consecutive Winter Olympics, starting in 1984 in Sarajevo, Yugoslavia, and three consecutive Summer Olympics, starting in 1988 in Seoul, South Korea. In her third Winter Olympic appearance, at the 1992 Winter Olympics in Albertville, France, she won the bronze medal in the women's 1500 metres event. Hashimoto participated for thirteen consecutive years in the World Allround Championships.
She is currently a member of the House of Councillors from the Liberal Democratic Party and the President of the Japan Skating Federation. Hashimoto served as state secretary (senior vice-minister) for foreign affairs under the Taro Aso administration (2008-2009).
Her father gave her the name Seiko, after the Olympic Flame (seika 聖火) when she was born in 1964, the year of the Tokyo Olympics.