Balan was born in the village of Kubey in the Russian Empire, today in Odessa Oblast, Ukraine, to a Bessarabian Bulgarian family. The Bulgarian general Georgi Todorov was his brother. Balan studied in Prague and Leipzig graduating in Slavistics from the Charles University in Prague. In 1884 he settled in Sofia, the capital of the Principality of Bulgaria, spending four years working for the Ministry of Popular Enlightenment. He became professor of Slavic ethnography and dialectology and history of the Bulgarian language, since 1893 head of the Bulgarian and Slavic literature department of the High Pedagogical School (the future Sofia University). On 29 January 1889, he was elected the first rector of the university and reelected several times (1896–1897, 1902–1903); he was also dean of the Faculty of History and Philosophy (1899–1900, 1904–1905).
In the late 19th and early 20th century, he was secretary of the Bulgarian Academy of Sciences, and from 1939 on he was doctor honoris causa of the Sofia University, as well as an active member of the Bulgarian Academy of Sciences. From 1907 to 1910 he was also the head secretary of the Bulgarian Exarchate. Aleksandar Teodorov-Balan was also among the founders of the tourist movement in Bulgaria, a long-standing chairman of the Bulgarian Tourist Association and editor of the Bulgarian Tourist magazine. In addition, he was also Grand Master of the Grand Masonic Lodge of Bulgaria.
Among his most important scientific contributions ranks his work on Bulgarian grammar, the peculiarities of Bulgarian phonology, his struggle against loanwords (linguistic purism), the enrichment of the language using dialectal words. He also published works in the field of literary history. Some of his publications (including posthumous) include:
- A study on Slavonic-Bulgarian History, Plovdiv, 1898
- Sophronius of Vratsa, Sofia, 1906
- Cyril and Methodius. Passionals, Sofia, 1920
- New Bulgarian grammar, Sofia, 1940
- Struggle for modern orthography (1921-1923), Sofia, 1924
- New Bulgarian grammar for everyone, Sofia, 1958
- Selected works, Sofia, 1987
- A book about myself, Sofia, 1988
Balan's scientific legacy amounts to 886 titles, including books, studies, articles and notes, of which 310 devoted to the Bulgarian language, as well as many successful neologisms. Despite his numerous contributions, Balan lived in relative poverty, with his French wife often suffering from tuberculosis. Balan survived to almost centenarian age, he died in Sofia on 12 February 1959.
- SCAR Composite Gazetteer of Antarctica: Balan Ridge.
- Грашева, Лиляна; et al. (2003). "Теодоров-Балан, Александър Стоянов". Кирило-Методиевска енциклопедия (in Bulgarian). София: изд. на БАН, Институт за литература; акад. издателство "Марин Дринов", т. IV (допълнения). pp. 44–47. ISBN 954-430-949-7. (АИ)(Т. IV); (ИЛ при БАН).
- "Александър Теодоров-Балан" (in Bulgarian). Bibliotheca Slavica. 2008-08-03.