David was born on July 6, 1941, to Frank Evans Wanlass and Josephine Robinson, in Nephi, Utah. He spent two years as a missionary for the Church of Jesus Christ of Latter-day Saints, in the West Virginia/Tennessee mission area.

David graduated from Brigham Young University in 1967 with a degree in Chemistry. He moved to Cornell University in New York where he earned a PhD in Physical Chemistry in 1971. David spent many years working for Intel Corporation in San Jose, California in the 1970s, and later for Source Technology, a computer hardware startup, in the 1980s. He contributed to many electronic patents, including those for solar panels and flat-screen technology.

David loved spending time with his family outdoors, going camping, hiking, skiing, and fishing. He also enjoyed playing the trombone and classical guitar and singing with church choirs. David was known for his sense of humor and his willingness to help others in need.

David married Marye Rowley in the Manti Temple in 1965. They are the parents of four daughters: Zara Wanlass (Jason Knight), Kjersha Naber (Devin Naber), Maia Wanlass, and Maryssa Wanlass (Mark Vashro). They have two grandchildren: Emma Josephine Holmes-Wanlass and Orlando Vashro-Wanlass.

David was preceded in death by his father and mother, Frank and Josephine, his brothers Frank, William, and Mark, and his sister, Joyce. He is survived by his brother John Wanlass, numerous nieces and nephews, and step-grandchildren.

David will be cremated and his final interment will be in Utah.