The Fall ORC Seminar schedule can be found here.
The Spring ORC Seminar schedule can be found here.
Subscribe to the ORC Seminar email list here.
Other related seminars:
The ORC Independent Activities Period (IAP) Seminar.
The Operations Management seminars.
MIT has a large number of related seminars including the Applied Math Colloquium, LIDS Seminar Series, CCE Seminars, and CSAIL Seminars.
The Harvard University Center for Mathematical Sciences and Applications also offeres related colloquia and seminars.