Lillian Katherine Haass (Chinese: 夏秀蘭, Xia Xiulan;[1] 26 November 1886 – 7 January 1964) was a YWCA worker in Shanghai, China, between 1914 and 1945.

[4] Haass wanted social and economic justice for Chinese factory workers, but as a Christian believed in peaceful, cooperative reform.

They would take the Orient Express across the Soviet Union and then study in a seminar held by Sherwood Eddy at the London School of Economics (LSE).

[7] The women took different routes, but met in London at the end of March 1924 and went on to Birmingham to attend the international Conference on Christian Politics, Economics and Cirizenship.

[8] By the mid-1920s it was becoming clear that to remain a relevant organization in China the YWCA had to pay more attention to the women in rural and industrial occupations and less to the middle classes.

[12] Haass argued unsuccessfully with Ding Shujing in late 1927 over the direction of the YWCA industrial program.

[14] At the time of the Shanghai massacre of 1927 Haas wrote, "Perhaps in Europe and America the YWCA does not question the capitalistic order; here in China we must—God be praised!

"[12] In 1927 Haass joined a political study group in Shanghai with progressive foreigners such as Rewi Alley, Maud Russell, Talitha Gerlach and Deng Yuzhi.

The Chinese had a real respect for nearly all the [YMCA] secretaries they worked with, particularly for such persons as Talitha Gerlach, Maud Russell, Lily Haass and a few others.

[26] In November 1964 the Wisconsin alumnus reported the death of Lily Katherine Haass, class of 1912, in Los Angeles, California.