Born in in Afula, Ariel served in a combat unit in the Israel Defense Forces and retired at the rank of major. He is a propnent of Israeli settlements, and worked on the Amana settlement movement, the Yesha Council, and the Beit El local council. He was also a member of the Jewish National Fund.
Ariel once declared his intention to build a synagogue on the Temple Mount, opposed Angela Merkel speaking to the Knesset, and argued against crackdowns on the "hilltop youth." He also sponsored a bill in 2011 to ban the use of Nazi references except in academic cases.
Ariel was appointed the Minister of Agriculture and Rural Development following the 2015 election.