Athanasios Papoulis[1] (Greek: Αθανάσιος Παπούλης; 1921 – April 25, 2002) was a Greek-American engineer and applied mathematician.

In 1945, he stowed away on a boat to escape the impending Greek Civil War and settled in the United States.

Two classic texts aimed at [engineering] practitioners were [first] published in 1965... [One was] Athanasios Papoulis' Probability, Random Variables, and Stochastic Processes...

[5]By staying away from complete mathematical rigor while emphasizing the physical and engineering interpretations of probability, Papoulis's book gained wide popularity.

Papoulis also taught and developed subjects such as stochastic simulation, mean square estimation, likelihood tests, maximum entropy methods, Monte Carlo method, spectral representations and estimation, sampling theory, bispectrum and system identification, cyclostationary processes, deterministic signals in noise (part of deterministic systems and dynamical system studies), wave optics and the Wiener and Kalman filters.