The present Lecture Notes in Statistical Mechanics were written for the students of the ICTP Diploma Course in Condensed Matter Physics at the Abdus Salam ICTP in Trieste, Italy.
The lectures cover classical and quantum statistical mechanics, however, some emphasis is put on classical spin systems. I give also an introduction to Bose condensation and superfluidity but I do not discuss phenomena specific to Fermi particles, being covered by other lecturers.