The direct train will also stop at Rotterdam.
"The launch of the London to Amsterdam service marks a historic milestone in the expansion of global high-speed rail travel, revolutionising the connection between these important destinations", the company said.
The journey will take three hours and 41 minutes from city to city.
Now those wishing to travel from London to Amsterdam by Eurostar had to change in Brussels in both directions, leaving a journey that took four hours and 38 minutes.
The launch of the new London-Amsterdam service, with two trains per day, will set a new travel-time record for the London-Brussels leg, Eurostar said.
The start of services follows an extensive period of testing on the Dutch high-speed network and the construction of Eurostar terminals in Amsterdam and Rotterdam.
Harrison is Mixmag's East Coast Editor.
The new Eurostar route will see two trains a day leave St Pancreas for the Netherlands capital - famed for it's weed-selling coffee shops and Red Light District. Over four million passengers travel by air between London and Amsterdam every year, and Eurostar clearly plans to cut itself a wedge of the transcontinental action.
Nicolas Petrovic, the outgoing chief executive of Eurostar, said the Netherlands service heralded a new era in worldwide high-speed rail.
A deal between the British and Dutch governments should be in place by the end of 2019, Eurostar said.
"With direct services from the United Kingdom to The Netherlands, France and Belgium, we are transforming the links between the United Kingdom and three of Europe's top trading nations".
This means passengers will have to change at Brussels, leaving the return journey time at an estimated four hours and 49 minutes.