The left-handed batting and throwing native of Fisherville, Tennessee was a two-time all-city baseball player at South Side High School in Memphis.

After turning down an offer to play alongside his older brother, Faye, with the Boston Red Sox, he signed as an amateur free agent with the New York Yankees in May 1952.

Throneberry made his major league debut as a pinch runner for Eddie Robinson on September 25, 1955 at Fenway Park.

Seeing most of his action as a pinch hitter or late inning defensive replacement at first, an injury to Bill Skowron on May 11 landed Throneberry in the starting line up through the rest of May.

After the season, he was part of the blockbuster trade that sent 1956 World Series hero Don Larsen, Hank Bauer and Norm Siebern to the Kansas City Athletics for power-hitting outfielder Roger Maris, Joe DeMaestri and Kent Hadley.

[8] But on May 24 at Municipal Stadium, he was inserted into the lineup at first base (Siebern moved to left field) and Throneberry went three for four, with a homer, double and triple, driving in three runs and leading the Athletics to a 6–2 victory over the Red Sox.

Finally, on June 21, Athletics manager Bob Elliott moved Siebern to left field on a semi-permanent basis and installed Throneberry at first base.

With an All-Star MVP candidate who batted left-handed in Jim Gentile at first base, the Orioles used Throneberry mostly as a pinch hitter or in right field.

On June 13, his ninth inning pinch hit single drove in Dick Hall for the walk off victory over the Washington Senators.

The Mets sent catcher Hobie Landrith, their first selection in the 1961 Major League Baseball expansion draft, to the Orioles to complete the deal.

Throneberry maintained a sense of humor about his play and became a favorite with fans and the media (after the season, he received the Ben Epstein Memorial "Good Guy" Award[15]).

"[16] In one famous story, on June 17, Throneberry hit a triple against the Cubs, but was called out after Ernie Banks took a relay throw and stepped on second base.

In the second game of a June 22 doubleheader with fellow expansion club, the Houston Colt .45s, Throneberry committed three of six Mets errors.

With the exception of one rough year defensively, Throneberry was no worse than average with his career fielding percentage and range factor (8.01) as a first baseman.

"[20][21] Columnist Jimmy Breslin quipped, "Having Marv Throneberry play for your team is like having Willie Sutton work for your bank.