ABSTRACT--This paper presents two optical fiber sensor configurations that are capable of simultaneously measuring temperature and strain. These sensor configurations use serial and parallel combinations of in-line fiber etalon (ILFE) and in-fiber Bragg grating sensors, along with wavelength division multiplexing concepts. The results obtained while simultaneously varying the temperature over 130~ and strain field over 1500 ItS showed favorable agreement with thermistors and resistance strain gages.