Seymour R. Thaler (August 31, 1919 – February 5, 1976) was an American lawyer and politician from New York.
He was born Seymour Thaler on August 31, 1919, in the East Bronx, New York City, the son of Jacob Thaler and Gussie Thaler. He added the middle initial R. to his name while still going to school. He attended Public School No. 63 and DeWitt Clinton High School. He graduated from Brooklyn College; and LL.B. and J.S.D. from Brooklyn Law School. He was admitted to the bar in 1942, and practiced law in New York City.
Thaler was a member of the New York State Senate from 1959 to 1971, sitting in the 172nd, 173rd, 174th, 175th, 176th, 177th, 178th, 179th and 180th New York State Legislatures. He was a delegate to the 1964 Democratic National Convention. In 1969, he ran in the Democratic primary for New York City Comptroller but was defeated by Abraham Beame.
In November 1971, he was elected to the New York Supreme Court. On December 21, he and three associates were indicted for selling $800,000 worth of stolen Treasury bills in 1970. On December 23, 1971, he pleaded not guilty. In February 1972, four counts of perjury were added to the indictment. On March 23, he was convicted of unlawfully receiving and disposing of stolen securities, and of perjury. On August 8, he was sentenced to one year in prison, and fined $10,000. On November 2, he was disbarred by the Appellate Division. On March 5, 1973, the conviction was upheld by the United States Court of Appeals for the Second Circuit.