Liia Hänni (née Juulik; born 4 October 1946) is an Estonian astrophysicist, social activist and former politician who voted for the Estonian restoration of Independence.

Born in Atla, Saare County, Liia Hänni graduated from Saaremaa gymnasium in 1965 and the University of Tartu's Department of Physics in 1970.

In 1986, the Observatory defended the candidate's thesis in astrophysics "Investigating the Atmosphere of Red Crayfish by the Synthetic Spectrum Method".

In 1992, she was elected to the Riigikogu as a member of what is now the Social Democratic Party (Jõgeva and Tartu electoral district).

Hänni is the program director of the e-Governance Academy, e-democracy and e-participation programs, and since 2011, Member of the Board of the EMSL Board of the Association of Free Alliances.