On April 30, 2017, Rendon went six-for-six with three home runs and 10 RBI in a 23–5 win over the division rival New York Mets. He became the 13th major leaguer with 10 or more RBI in one game while setting a Nationals record. He became the third player in major league history attain both six hits and ten RBI in the same game, following Jim Bottomley (1924) and Walker Cooper (1949).
Despite leading all National League position players in wins above replacement during the first half of the season, Rendon was not selected to participate in the All-Star Game. He was one of the options in the "final vote" but lost out to Justin Turner of the Los Angeles Dodgers. Despite the All-Star snub, Rendon was named as Player of the Week in the National League on July 17, 2017, for the week abbreviated by the All-Star break. It was his first time so honored. Rendon hit .636 during the week with three home runs to earn the award. In 2017, he batted .301/.403/.533 with 25 home runs.
Rendon is frequently described by sports media as quiet and modest, qualities that when combined with his strong all-around offensive and defensive performance as an infielder for the Washington Nationals have led some, including 2016–17 Nationals manager Dusty Baker, to dub him one of the most "underrated" players in Major League Baseball. Explaining his philosophy on baseball to The Washington Post during spring training in 2017, Rendon said, "Obviously, I want to win, but at the same time, at the end of the day, it’s a game and that’s what I’m going to treat it as." He claimed in a 2014 interview with the Post that he prefers watching the History channel to baseball, calling the sport "too long and boring".
An avid basketball fan, Rendon follows the Houston Rockets, his hometown NBA team. He has maintained close ties to the Houston area. In the aftermath of Hurricane Harvey in August 2017, Rendon and then Nationals teammate Matt Albers, a fellow Houstonian, set up a YouCaring fundraiser page to raise money for donations to the Houston Food Bank.