The army, in a joint statement with the Shin Bet security agency, did not disclose the number of people arrested, but added that "forces also located the weapon and vehicle used to execute the attack".
It said in the English-language statement that one of the suspects "during the investigation ... Associated himself in the involvement in the attack" on Friday in the occupied West Bank.
The 40-year-old father and 18-year-old son, Yaakov and Netanel Litman, were ambushed and shot dead as they drove near the Jewish settlement of Otniel, south of Hebron, in the bloodiest attack on Israelis in nearly a month.
Their murders sparked a manhunt, with soldiers backed by air units deploying in the neighbouring Palestinian communities of Yatta and As Samou.
More From This Section
The shooting deaths of two Israeli settlers in front of their children in the northern West Bank on October 1 was the first incident in a weeks-long wave of gun, knife and car-ramming attacks by Palestinians.
Violence since the start of October has killed 81 people on the Palestinian side - including one Arab Israeli - and 12 Israelis.