Don Grady
AKA Don Louis Agrati
Born: 8-Jun-1944
Birthplace: San Francisco, CA
Died: 27-Jun-2012
Location of death: Thousand Oaks, CA
Cause of death: Cancer – unspecified
Gender: Male
Race or Ethnicity: White
Occupation: Actor
Nationality: United States
Executive summary: Robbie Douglas on My Three Sons
Grady was born Don Louis Agrati in San Diego, California, the son of Mary B. (née Castellino), a talent agent, and Lou A. Agrati, a sausage maker. He grew up in Lafayette, California, and attended Lafayette Elementary School (where he served as school president); Stanley Junior High, where he spent only a few months before being signed by Disney and leaving the area;[2] and Burbank High School (pictured as Don Agrati).
His acting credits included several Western series, including John Payne’s The Restless Gun, Dick Powell’s Zane Grey Theater, Wagon Train and The Rifleman, where he played two roles in Season 2; ‘Jeff Barrows’, a barber’s son, in Episode 1 and ‘David Chase’ sister to the title character ‘Heller’ in Episode 22. He also had a role in the NBC medical drama, The Eleventh Hour. Originally the frustrated middle brother on My Three Sons, he became the confident elder brother with the departure of Mike (Tim Considine, who had earlier appeared with Grady in The New Adventures of Spin and Marty), and the adoption of Ernie (Barry Livingston), who became the new “third son.”
During production of My Three Sons, Grady both appeared with his own band The Greefs on the series, and was the drummer for The Yellow Balloon, whose self-titled song became a minor hit during 1967. For a while during the run of the series, he attended Los Angeles City College.
Grady died of cancer June 27, 2012, in Thousand Oaks, California.

don thanks for all the enjoyment on my three sons rest in peace good friend.