Mineko Iwasaki (岩崎 峰子/岩崎 究香, Iwasaki Mineko; born Masako Tanaka (田中 政子), 2 November 1949) is a Japanese businesswoman, author and former geisha. Iwasaki was the most famous geisha in Japan until her sudden retirement at the age of 29. Known for her performances for celebrity and royalty during her geisha life, Iwasaki was the heir apparent (atotori) to her geisha house (okiya) while she was just a young apprentice.

American author Arthur Golden interviewed her for background information when writing his 1997 book, Memoirs of a Geisha. Iwasaki later regretted interviewing for Golden, having cited a breach of confidentiality, and later sued and settled out of court with Golden for the parallelism between his book and her life. In 2002, she released her own autobiography, titled Geisha of Gion in the UK and Geisha: A Life in the US.