SMART-S Mk2[2][5][4] (Signaal Multibeam Acquisition Radar for Tracking, S band Mk2) is a naval medium to long-range air and surface surveillance multibeam passive electronically scanned array 3D radar designed by Thales Nederland,[6] formerly Hollandse Signaalapparaten (Signaal).

While the original SMART-S radar was only produced in small numbers, SMART-S Mk2 is more successful with 30 systems were sold to navies all over the world within six years after being introduced.

[1][7] The system has two operating modes: medium range up to 150 km (81 nmi) at 27 RPM and long range up to 250 km (130 nmi) at 13.5 RPM.

The radar mainly designed for light frigates, corvettes and ships such as Landing Platform Docks (LPD).

SMART-S Mk2 is designed to support full performance of surface to air missiles (SAM), such as the RIM-162 ESSM.