The B class as designated in 1913 was a heterogeneous group of torpedo boat destroyers (TBDs) built for the Royal Navy in the late 1890s.

All "30 knotter" vessels with four funnels were classified by the Admiralty as the B class in 1913 to provide some system to the naming of HM destroyers.

Fourteen vessels were built by Laird Brothers at Birkenhead (in 1903 to become part of Cammell Laird, Birkenhead), seven by Palmers Shipbuilding and Iron Company at Hebburn-on-Tyne, and one each by Armstrong Whitworth at Walker-on-Tyne, William Doxford and Sons at Sunderland, and J & G Thomson (later to become John Brown and Company) at Clydebank.

They generally displaced around 350 tons, one third more than the preceding A class, giving an increase in speed of 3 knots (5.6 km/h) over the "27 knotters".

The last two Palmers boats, built in 1908, were replacements for the River-class Gala and the C-class Tiger that had collided and sunk that year.