Halbarad (Sindar for 'Tall Tower') (d. March 15, 3019) was a Ranger of the North, leader of the Grey Company. Halbarad was among the Rangers who guarded the Shire. He said of the Hobbits, "A little people, but of great worth are the Shire-folk. Little do they know of our long labor for the safekeeping of their borders, and yet I grudge it not." 
In response to a message sent to Rivendell by Galadriel, Halbarad led the Grey Company comprised of 30 Dunedain south to the aid of their kinsman Aragorn. Aragorn rejoiced at their coming, and king Théoden remarked thus; "It is well! If these kinsmen be in any way like yourself, my Lord Aragorn, thirty such knights will be a strength that cannot be counted by heads."
With them also rode Elladan and Elrohir, the sons of Elrond. They caught up with Aragorn near the Fords of Isen in Rohan in the early hours of March 6, 3019. Halbarad brought Aragorn a message from Arwen as well as a standard made by her, which Aragorn asked Halbarad to keep for him for a while.
Halbarad accompanied Aragorn to a chamber high in the Hornburg where Aragorn looked into the palantir and revealed himself to Sauron. That morning Aragorn decided to take the Paths of the Dead, down the Dimholt Road, under the White Mountains and Halbarad and Grey Company went with him along with Legolas and Gimli. When they reached the entrance at daybreak on March 8, Halbarad said, "This is an evil door, and my death lies beyond it. I will dare to pass it nonetheless..." 
At midnight at the Stone of Erech, Aragorn summoned the Dead to fulfill their oaths and Halbarad unfurled Aragorn's standard, which appeared black with no device in the darkness. The Grey Company and the Army of the Dead passed through the lands of the South to Pelargir, where they captured the fleet of the Corsairs. Aragorn dismissed the Dead, and the Grey Company sailed up the Anduin.
When they arrived at the Pelennor Fields on March 15 in the midst of the battle, Aragorn's standard was once again unfurled but now it was seen to bear the emblem of the White Tree of Gondor and the Seven Stars and Crown of Elendil. Halbarad carried the standard onto the battlefield, where he was killed.
Appearances in adaptations
In The Lord of the Rings (1981 radio series), Halbarad was voiced by the actor Martyn Read. In The Lord of the Rings Online Halbarad first appears as commander of Esteldin, a hidden Dúnedain city in the North Downs. He later becomes the leader of the Grey Company and leads them from Rivendell, through Eregion, Enedwaith and Dunland south, to aid Aragorn in Rohan
Halbarad also appears in a fan-made film Born of Hope.
Halbarad appears in the recent video game Lord of the Rings: War in the North as the leader of the Dúnedain guarding the Shire camped at Sarn Ford. He sends the player's party on a quest to the Barrow Downs to locate two lost rangers, Luin and Kilaren. He is modeled with greying hair and a large beard in this adaptation.