[2] Robart received a Bachelor of Arts degree magna cum laude from Whitman College in 1969 and a Juris Doctor from Georgetown University Law Center in 1973.

[5][3] He also was a legislative assistant to United States Representative John Dellenback and worked with Henry M. "Scoop" Jackson on the Alaska Native Claims Settlement Act.

[1] He received a unanimous "well-qualified" rating from the American Bar Association's Standing Committee on the Federal Judiciary.

"[21] Robart was assigned to Microsoft v. United States, a case brought in 2016 by Microsoft Corp. (with support by other tech companies, including Apple, Google, and Amazon) against the U.S. Department of Justice, challenging the provision of the federal Stored Communications Act that bars companies from alerting customers to secret government surveillance of their emails.

In February 2017, Robart denied the government's motion to dismiss, finding that Microsoft had made a plausible First Amendment argument that these "gag orders" were akin to "permanent injunctions preventing speech from taking place before it occurs" and therefore failed strict scrutiny.

Robart wrote: "The public debate has intensified as people increasingly store their information in the cloud and on devices with significant storage capacity.

[27] On February 9, a three-judge panel of the Ninth Circuit unanimously upheld Robart's order and rejected the federal government's request for an emergency stay pending appeal.

[30] On July 24, 2020, Robart granted a restraining order on behalf of the justice department overruling a Seattle city ban on the use of teargas and impact munitions.

[6][31] Robart is an avid fisherman and has for many years taken annual fishing trips to Langara Island, British Columbia.