Approximately 120 soldiers from the 5th Battalion The Rifles arrived at the Amari Airbase on Friday, around 25 miles southwest of Estonian capital Tallinn.
Upon their arrival from RAF Brize Norton, the troops were welcomed by the country's defense minister, Margus Tsahkna.
Eight hundred British soldiers will be stationed in Estonia as part of one the biggest NATO military deployments to eastern Europe in decades.
The first batch of soldiers will set up a United Kingdom headquarters in the country before the rest arrive next month.
According to the United Kingdom ministry of defense, the soldiers will work alongside French and Danish forces to "Provide a proportionate, defensive, and combat capable force to defend our NATO ally and deter any form of hostile activity against the alliance."
Britain will take the lead in the Estonia battlegroup, while other nations deploy troops to Latvia, Lithuania, and Poland as part of NATO'S Enhanced Forward Presence Battalion.
Approximately 300 UK vehicles also left by ferry this week, headed for Estonia. They include Challenger 2 tanks, Warrior infantry fighting vehicles, and AS90 self-propelled artillery pieces.
Britain and Estonia have a long history of military cooperation.
According to United Kingdom defense secretary Sir Michael Fallon, due to an increasingly assertive Russia, NATO is stepping up its commitment to collective defense.
Fallon added that the British troops will play a leading role in Estonia, and support their US allies in Poland.