He was received by officials from the defence and foreign ministries at the Nur Khan Airbase, Chaklala.
The US defence secretary is expected to meet Pakistan Prime Minister Shahid Khaqan Abbasi and Chief of Army Staff General Qamar Javed Bajwa.
Mattis had, on Sunday, said he would want to find a common ground to work together with Pakistan.
Reportedly, the defence secretary was asked en route to Kuwait if he would prod Pakistan, to address its alleged support for the militants, when he visits there.
In his response, Mattis said, "That's not the way I deal with issues. I believe that we work hard on finding the common ground and then we work together."
Mattis had, in October, said the US would try "one more time" to work with Islamabad before taking "whatever steps are necessary",
Mattis' visit comes days after the release of Lashkar-e-Taiba (LeT) leader Hafiz Saeed from house arrest in Pakistan following which the United States had strongly condemned Islamabad and called for his immediate re-arrest and prosecution.
The White House, in a statement, had said: "The United States strongly condemns the release of Lashkar-e-Tayyiba (LeT) leader Haft Saeed from house arrest in Pakistan and calls for his immediate re-arrest and prosecution." (ANI)