Mike Lookinland's father was a Vice Principal at San Pedro High School, located in San Pedro, California, part of the Los Angeles Unified School District (LAUSD), in the late 1970s. Lookinland grew up as a Mormon. He is a self-professed conservationist and "camping nut". He attended the private Chadwick School on the Palos Verdes Peninsula in Southern California, and graduated in 1978.

Lookinland was a TV commercial actor before he was cast in The Brady Bunch, having done around thirty commercials. He has naturally sandy-colored wavy hair. Because his hair color did not match Peter's or Greg's natural dark brown color, he had to have his hair dyed dark brown and straightened to match. Occasionally, the lights on set though were so hot that his dye job would sometimes run down his face. During the last two seasons of The Brady Bunch, his natural hair color was finally allowed to show. Bobby (Mike) was always the type of kid who was sweet, funny, energetic, and sometimes dramatic during his role on the Brady Bunch.

In a classic Brady Bunch episode during its final season, Bobby kisses Melissa Sue Anderson and he sees “sky rockets.” Her character, “Milicent,” then informs him that she may have the mumps and he "shouldn't have done that." Bobby and his family nervously await her telephone call with the doctor's results. Years later, the two reunited on Melissa's television series Little House on the Prairie. This time, Mary's character Mary Ingalls has just been cheated on and dumped by her childhood fiancee John in Chicago. She meets Lookinland's character on a train trip home and they shares sandwiches together. In this scene, Lookinland's very curly blonde hair is quite apparent.

Lookinland also provided the voice of Oblio in the animated film The Point!. Shortly after the final season of The Brady Bunch wrapped filming, he appeared alongside Jennifer Jones and Paul Newman in the 1974 disaster film The Towering Inferno and in The Secrets of Isis.

Since 1987, he has been married to Kelly Wermuth. Kelly worked as a script supervisor on Touched By An Angel. They have two sons: Scott (born 1990) and Joe (born 1993). He was portrayed by his son Scott in the TV movie Growing Up Brady. He was arrested in 1997 with a DUI after crashing his Ford Bronco. He has since been sober.

Lookinland reprised his role as Bobby Brady in the 1988 Christmas special A Very Brady Christmas, and again in the 1990 sequel series The Bradys, in which Bobby Brady had a racing car accident which caused him to use a wheelchair throughout the series.

Lookinland's younger brother, Todd, is also an actor. He appeared in a Brady Bunch episode that was really a pilot about a husband and wife that adopt 3 boys, one white, one black, and one Asian. The pilot was not bought however.

Out of the six Brady Bunch kids, he and Maureen McCormick, are the only two who have not been divorced.