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 4 of 6 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 4 Niles Fitch, aka Teenage Randall Age on the show: 15 Age in real life: 16 Previous Next Start Slideshow This Is UsFall TVTVCelebrity Facts