Ted Crawford Sizemore (born April 15, 1945) is an American former professional baseball player. He played in Major League Baseball as a second baseman from 1969 to 1980 for the Los Angeles Dodgers, St. Louis Cardinals, Philadelphia Phillies, Chicago Cubs, and Boston Red Sox. After winning the National League's Rookie of the Year Award in 1969, his promising career was restricted by numerous injuries. After his playing career, Sizemore worked for Rawlings Sporting Goods.

Sizemore was born in Gadsden, Alabama, but moved to Detroit, at the age of two years. As a catcher for Pershing High School's baseball team, he earned All-city honors three times. He also earned All-city honors playing fullback in football and guard in basketball twice each. He was high school teammates with Basketball Hall of Famer Mel Daniels playing under coach Will Robinson.

At the University of Michigan at Ann Arbor, he was a varsity letterman from 1964 to 1966, and received All-Big Ten honors in 1965 and 1966. In 1966, he batted .321 to receive District All-America honors. In 1982, the university created the "Ted Sizemore Award" to honor the school's top defensive player each season.

The Los Angeles Dodgers selected Sizemore in the fifteenth round of the 1966 Major League Baseball draft. He served strictly as a catcher his first professional season, but his bat (.330, 4 home runs and 37 RBIs for the Northwest League's Tri-City Atoms) prompted the Dodgers organization to try him more in the outfield in 1967 and 1968. In need of infielders, the Dodgers had Sizemore play second base in the Winter Instructional League in 1968. Following Zoilo Versalles' departure in the 1968 Major League Baseball expansion draft, manager Walter Alston shifted Sizemore over to shortstop at the beginning of Spring training 1969.

Sizemore won the starting shortstop job that spring. Despite a two error performance against the San Francisco Giants, Sizemore proved himself an adequate shortstop. Still, with second baseman Jim Lefebvre not hitting, Sizemore began seeing more time at second by the end of his first month in the majors. With Maury Wills' acquisition on June 11, the move became permanent.

With his bat, Sizemore got off to a hot start in his rookie season, but cooled off in June and July. He picked it up again in the final two months of the season to finish at .271 with four home runs 46 runs batted in and 69 runs scored. He received fourteen of 24 first place votes to be named the National League's Rookie of the Year.

Sizemore got off to a slow start in 1970. He was batting .257 with one home run, twelve RBIs and fourteen runs scored when he ruptured his thigh muscle on June 11 against the St. Louis Cardinals. He returned in late July, and his hitting actually improved. He batted .342 to bring his season average to .306 until a sprained wrist ended his season. That winter, he and minor league catcher Bob Stinson were traded to the Cardinals for slugging first baseman Dick Allen.

He began his tenure with the Cardinals splitting time between shortstop and second base, but as the 1971 season wore on, he began taking more and more playing time away from veteran Julián Javier at second. He batted .264 each of his first two seasons in St. Louis. His finest season came in 1973, when he put up career highs in batting (.282), RBIs (54) and runs (69, tying the career high he set his rookie season), while leading the National League in Sacrifice Hits with 25. In 1974, Sizemore usually batted second behind Hall of Famer Lou Brock. Brock set a record with 118 stolen bases that season, and credited Sizemore's patience at the plate batting behind him as a big factor.