[2] He attended Allan Glen's School and graduated from the University of Glasgow with a bachelor's degree (BSc) in 1928.

Todd was awarded an 1851 Research Fellowship from the Royal Commission for the Exhibition of 1851,[3] and, after studying at Oriel College, Oxford, he received another doctorate (DPhil) in 1933.

In 1938, Alexander Todd spent six months as a visiting professor at California Institute of Technology, eventually declining an offer of faculty position.

[4][5] Todd became the Sir Samuel Hall Chair of Chemistry and director of the Chemical Laboratories of the University of Manchester in 1938, where he began working on nucleosides, compounds that form the structural units of nucleic acids (DNA and RNA).

Among his many honours, including over 40 honorary degrees, he was elected a Fellow of the Royal Society in 1942, a member of the United States National Academy of Sciences in 1955,[11] a member of the American Academy of Arts and Sciences in 1957,[12] and the American Philosophical Society in 1965.