Anthony Michael Lazzeri (December 6, 1903 – August 6, 1946) was an American professional baseball second baseman during the 1920s and 1930s, predominantly with the New York Yankees of Major League Baseball (MLB). He was part of the famed "Murderers' Row" Yankee batting lineup of the late 1920s (including the 1927 team), along with Babe Ruth, Lou Gehrig, and Bob Meusel.

Lazzeri was born and raised in San Francisco, California. He dropped out of school to work with his father as a boilermaker, but at the age of 18, began to play baseball professionally. After playing in minor league baseball from 1922 through 1925, Lazzeri joined the Yankees in 1926. He was a member of the original American League All-Star team in 1933. He was nicknamed "Poosh 'Em Up" by Italian-speaking fans, from a mistranslation of an Italian phrase meaning to "hit it out" (hit a home run).

Lazzeri is one of only 14 major league baseball players to hit for the natural cycle (hitting a single, double, triple and home run in sequence) and the only player to complete a natural cycle with a grand slam. He also holds the American League record for the most RBI in a single game, with 11 on May 24, 1936. In that same 1936 game, he became the first major league player to hit two grand slams in one game. Lazzeri was posthumously inducted into the National Baseball Hall of Fame by the Veterans Committee in 1991.

Lazzeri was born on December 6, 1903, to Augustine and Julia Lazzeri, who had emigrated from Italy. They lived in the Cow Hollow district of San Francisco. Augustine worked as a boilermaker.

At age 15, Lazzeri was expelled from school. He began to work with his father, earning $4.50 a day ($94 in current dollar terms). Lazzeri also played semi-professional baseball and trained to become a prizefighter.

A friend of Lazzeri convinced Duffy Lewis, who managed the Salt Lake City Bees of the Pacific Coast League (PCL), to allow Lazzeri to try out for the team in 1922. Lazzeri made the team, earning $250 a month ($4,696 in current dollar terms) as a utility infielder. He batted .192 in 45 games, and was demoted to the Peoria Tractors of the Illinois–Indiana–Iowa League in 1923 to gain more experience.

Lazzeri batted .248 with 14 home runs in 135 games for Peoria, before being recalled to Salt Lake City. Starting at shortstop for the Bees in 1924, Lazzeri batted .285 with 16 home runs. However, Lewis gave the starting shortstop role to Pinky Pittenger, and sent Lazzeri to the Lincoln Links of the Western League, where he batted .329 with 28 home runs in 82 games.

Returning to Salt Lake City under new manager Oscar Vitt in 1925, Lazzeri batted .355 with 60 home runs and 222 runs batted in (RBIs), the most RBIs in professional baseball history. That year he became one of what are today four Pacific Coast League hitters to have had a 30 home runs, 30 stolen bases season, along with Joc Pederson (2014), Frank Demaree (1934), and Lefty O'Doul (1927). Though Salt Lake City had a working agreement with the Chicago Cubs, the Cubs passed on Lazzeri due to his epilepsy. The Cincinnati Reds passed on Lazzeri as well. Bill Essick, a scout for the New York Yankees, convinced Ed Barrow, the Yankees' general manager, to sign Lazzeri. Barrow agreed after receiving confirmatory reports from other scouts, including Ed Holly and Paul Krichell, as well as ensuring that Lazzeri's insurance policy would cover his illness.