Zhou was born Zhou Yaoping in Changzhou, Jiangsu Province, on 13 January 1906 to a Qing Dynasty official. At the age of ten, he and his family moved to Suzhou, Jiangsu Province. In 1918, he entered Changzhou High School, during which time he first took an interest in linguistics. He graduated in 1923 with honours.

Zhou enrolled that same year in St. John's University, Shanghai where he majored in economics and took supplementary coursework in linguistics. He was almost unable to attend due to his family's poverty, but friends and relatives raised 200 yuan for the admission fee, and also helped him pay for tuition. He left during the May Thirtieth Movement of 1925 and transferred to Guanghua University, from which he graduated in 1927.

On 30 April 1933, Zhou married Zhang Yunhe (张允和). The couple went to Japan for Zhou's studies. Zhou started as an exchange student at the University of Tokyo, later transferring to Kyoto University due to his admiration of the Japanese Marxist Economist Hajime Kawakami, who was a professor there at the time. Kawakami's arrest for joining the outlawed Japanese Communist Party in January 1933 meant that Zhou could not be his student. Zhou's son, Zhou Xiaoping (周晓平), was born in 1934. The couple also had a daughter, Zhou Xiaohe (周小禾).

In 1937, due to the outbreak of the Second Sino-Japanese War, Zhou and his family moved to the wartime capital Chongqing, and his daughter died. He worked for Sin Hua Bank before entering public Service as a deputy Director at the National Government's Ministry of Economic Affairs, agricultural policy bureau (经济部农本局). After the 1945 Japanese defeat in World War II, Zhou went back to work for Sin Hua where he was stationed overseas: first in New York City and then in London. During his time in the United States, he met Albert Einstein twice.

Zhou participated for a time in the China Democratic National Construction Association, but when the People's Republic was established in 1949 he returned to Shanghai, where he taught economics at Fudan University for several years.

In 1955, the Chinese government placed Zhou at the head of a committee to reform the Chinese language to increase literacy. While other committees oversaw the tasks of promulgating Mandarin Chinese as the national language and creating simplified Chinese characters, Zhou's committee was charged with developing a romanization to represent the pronunciation of Chinese characters. Zhou said the task took about three years, and was a full-time job. Pinyin was made the official romanization in 1958, although (as now) it was only a pronunciation guide, not a substitute writing system. Zhou based Pinyin on several preexisting systems: the phonemes were inspired by Gwoyeu Romatzyh of 1928 and Latinxua Sin Wenz of 1931, while the diacritic markings representing tones were inspired by zhuyin.

In April 1979, the International Organization for Standardization (ISO) in Warsaw held a Technology conference. Speaking on behalf of the People's Republic of China, Zhou proposed the use of the "Hanyu Pinyin System" as the international standard for the spelling of Chinese. Following a vote in 1982 the scheme became ISO 7098.

After 1980, Zhou worked with Liu Zunqi and Chien Wei-zang on translating the Encyclopædia Britannica into Chinese, earning him the nickname "Encyclopedia Zhou". Zhou continued writing and publishing after the creation of Pinyin; for Example, his book 中国语文的时代演进 (Zhōngguó yǔwén de shídài yǎnjìn), translated into English by Zhang Liqing, was published in 2003 as The Historical Evolution of Chinese Languages and Scripts. From 2000, he wrote ten books, of which some have been banned in China.

Zhou was the author of more than 40 books, some of them banned in China and over 10 of them published after he turned 100 in 2005.

Google honored what would have been his 112th birthday with an animated version of its logo in Mandarin.

In early 2013, both Zhou and his son were interviewed by Dr. Adeline Yen Mah at their residence in Beijing. Mah documented the visit in a video and presented Zhou with a Pinyin game she created for the iPad. Zhou became a Supercentenarian on 13 January 2016 when he reached the age of 110. He was one of the few supercentenarians, along with Herman Smith-Johannsen and Leopold Vietoris, known for reasons other than their longevity.

Zhou died on 14 January 2017 at his home in Beijing, the day after his 111th birthday; no cause was given. His wife had died in 2002, and his son had died in 2015. At the time, he was the seventh-oldest known living man and the oldest known living person in China. He is one of the 100 world's verified oldest men in history.