Highly sensitive Europium doped SrSO₄ optically stimulated luminescent (OSL) phosphor was developed by synthesizing a nano phosphor which is treated at 1000°C. Excellent OSL properties are observed in the developed phosphor and the sensitivity is found to be 1.26 times to that of the commercial Al₂O₃:C (Landauer Inc.) phosphor based on area integration method. The sample showed a single TL glow peak around 230°C which is found to reduce by 47% after the OSL readout. Sublinear dose response with the saturation around 100 mGy is observed in this sample which suggests that it is extremely sensitive and hence will be suitable in detecting very low dose levels. Minimum measurable dose on the used set up is estimated to be 1.42 l Gy. Practically no fading is observed for first ten days and the phosphor has excellent reusability. High sensitivity, low fading, excellent reusability will make this phosphor suitable for radiation dosimetry applications using OSL.