Kim Jong Un led a delegation of senior government and military officials in a moment of silence and "gun salute" at the Kamsusan Palace of the Sun.
Similar ceremonies were held throughout North Korea to commemorate Kim Jong Il's death from a heart attack in December, the official Korean Central News Agency said.
South Korea's Yonhap news agency said Sunday the memorial was a show of solidarity amid tensions over North Korea's plan to launch a satellite into orbit aboard a long-range missile. The launch threatens to derail a deal with the United States in which Pyongyang would suspend its missile program in exchange for food aid.
U.S. President Barack Obama and other world leaders will be in Seoul this week for a nuclear security summit during which the planned April launch will be a major topic of discussion, Yonhap said.