"If I am here for one more term, my kids will only ever have known me as a weekend dad. I can't let that happen," the 48-year-old Wisconsin Republican told reporters.
Ryan, who has been in Congress since 1999, will serve out the remainder of his term and leave office in January. The congressman cast it as a personal decision to see more of his teenage children before they are fully grown.
The House speaker said believes he "achieved a heck of a lot" as speaker, a position he accepted reluctantly. He highlighted the Republican tax law passed in December and the massive increase in military spending signed into law last month as his biggest achievements.