The “Old Oligarch” is the name commonly given by modern scholars to the author of this anonymous treatise on the government of Athens, which was preserved among the writings of the Athenian historian and thinker, Xenophon (born c. 430). Technically it is called pseudo-Xenophon's Constitution of the Athenians. The date of the treatise is uncertain, but the consensus is that it was written after 446 (because of events mentioned in 3.11) but probably before 424 (because of an event not mentioned in 2.5).

The author may be an Athenian in exile, for he speaks of Athenians as “they” (1.1 etc.) but also as “we” (1.12 etc.). He disapproves of their democratic constitution but admires the skill with which they have implemented this system. His style is very uneven, and the purpose of the treatise has long puzzled scholars. In our view the treatise belongs to the fifth-century debate about the relative merits of different constitutions and may have been an exercise that, like the Dissoi Logoi, required the assessment of both pros and cons.

[1] My subject is the constitution (politeia) of the Athenians. I do not approve their choice of this type of constitution, for in making their choice they preferred the well-being of the inferior class (ponēroi) at the expense of the better class (chrēstoi). For this reason, then, I do not approve of it.