National Grid (NGG) 6-K National Grid plc ('National Grid') Director's Other Appointment

Exhibit 99.1

11 May 2018

National Grid plc ('National Grid')
Director's Other Appointment

In accordance with Listing Rule 9.6.14(2), National Grid notes that Dean Seavers, US Executive Director and a member of the National Grid plc Board is appointed as a Non-executive Director of Albemarle Corporation, a US company quoted on the New York Stock Exchange, with effect from 8 May 2018.

Contact:

Ceri James, Assistant Company Secretary (+44 20 7004 3116)