Popsugar Entertainment This Is Us How Old Are the Kids on This Is Us? A This Is Us Age Investigation: How Old Are Young Randall, Kate, and Kevin in Real Life? November 21, 2017 by Terry Carter View On One Page Photo 1 of 6 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 1 Mackenzie Hancsicsak, aka Adolescent Kate Age on the show: 8-10 Age in real life: 10 Previous Next Start Slideshow This Is UsFall TVTVCelebrity Facts