Louis Agassiz Shaw II (1906–1987) was an American socialite, writer and murderer.

Shaw was born to Robert Gould Shaw II and Mary Hannington; the Shaws were a wealthy and influential Boston family. His father was a cousin of Colonel Robert Gould Shaw, noted for leading an African-American regiment in the Union Army during the Civil War.

He attended private school and Harvard University, where he graduated in 1929. Like Robert Gould Shaw, he was a member of the Porcellian Club, a men's-only final club at Harvard.

Upon graduation Shaw published a novel, Pavement (1929), using his nickname "Louis Second" as a pen name. He lived in a sprawling 15-room mansion in Topsfield, a town founded by the Gould family. According to Alex Beam's Gracefully Insane (a history of McLean Hospital, where Shaw spent the last years of his life) Shaw kept a copy of the Social Register next to the telephone and instructed his staff to refuse calls from anyone not listed. He often rode his horse along a bridle path from his estate, and through the area now known as the Ipswich River Wildlife Sanctuary, in order to reach the Myopia Hunt Club.^[1]

Like his elder half-brother Robert Gould Shaw III, Shaw struggled with depression and alcoholism.^[2] In 1964 he strangled his 64-year-old maid, who he said was plotting to murder him in his sleep. He confessed but pleaded not guilty; he was committed to Danvers State Hospital and later McLean, where he lived for 23 years.^[1][3]

Much of his art collection, which he intended to donate to the Fogg Museum, was discovered to be fakes.^[4]

• Pavement (1929)