Known for his ability to get on base, while he was still a minor leaguer, Youkilis was nicknamed "Euclis: The Greek God of Walks" in the best-selling book, Moneyball: The Art of Winning an Unfair Game.

A Gold Glove Award-winning first baseman, he once held baseball's record for most consecutive errorless games at first base (later broken by Casey Kotchman).

An intense performer on the playing field, Youkilis was known for his scrappiness, grittiness, dirt-stained jerseys, home-plate collisions, and his strange batting stance.

[5] As Jackie MacMullan wrote for the Boston Globe: "He does not look like an MVP candidate; more a refrigerator repairman, a butcher, the man selling hammers behind the counter at the True Value hardware store.

Youkilis was the hitting coach for Team Israel, under manager Ian Kinsler, when it competed in the 2023 World Baseball Classic in Miami, Florida.

He was a four-year letter winner, a two-time All-Greater Miami Conference (1996 and 1997) and All-City (1996 and 1997) player, and All-State his senior season as he led the team with a .475 batting average and finished second all time in home runs.

[39] After the 2002 season, Boston's then-assistant general manager, Theo Epstein, sent Youkilis to the Athletes' Performance Institute in Tempe, Arizona, where he engaged in an intensive six-week training regimen.

[56][57] On September 24, which was Yom Kippur, Youkilis appeared in the dugout in uniform, but declined to participate in the game out of deference to the religious holiday.

"[59] He was on the roster for the Red Sox for the 2004 American League Division Series (ALDS), making his sole appearance in Game 2 against the Anaheim Angels.

[62] Up and down all season as the Red Sox made use of his options, he got a call-up—prompted by Bill Mueller having back spasms in batting practice—one August day as he was in Pawtucket's clubhouse before a game.

On September 18, he fractured the tip of the ring finger of his right hand fielding a ground ball, and did not play again until October 2, the final day of the regular season.

Youkilis tied for the major league lead in sacrifice flies (11), and led the AL with 4.43 pitches per plate appearance and by hitting line drives 24% of time that he put balls in play.

"[75] On June 25, 2007, Youkilis played in his 120th consecutive game at first base without an error, breaking the prior Red Sox record set in 1921 by Stuffy McInnis.

"[80] Leading the league with a perfect 1.000 fielding percentage, and an AL-record 1,079 error-less chances at first, Youkilis won the 2007 AL Gold Glove award for first basemen.

[94] In an early June game at Fenway Park, one camera reportedly showed Manny Ramirez taking a swing at Youkilis, and the two had to be separated by teammates in the Red Sox dugout.

[96][97] Youkilis became the sixth Red Sox first baseman to start an All-Star Game at first base, following Jimmie Foxx (1938; 40), Walt Dropo (1950), Mickey Vernon (1956), George Scott (1966), and Mo Vaughn (1996).

[99] In 2008, Youkilis led the AL in at bats per RBI (4.7), was third in slugging percentage (.569) and sacrifice flies (9), fourth in RBI (115), extra base hits (76), and OPS (.958); fifth in hit by pitch (12); sixth in batting average (.312) and on-base percentage (.390); seventh in doubles (43) and in times advanced from first to third on a single (14); eighth in total bases (306), 10th in at-bats per home run (18.6), and 12th in home runs (29).

[102] Youkilis finished third in the balloting for the 2008 AL MVP Award, receiving two first-place votes (one from Evan Grant of The Dallas Morning News), while his teammate Dustin Pedroia won and Justin Morneau came in second.

[115] On August 8, he again played left field, and made a couple of twists and turns on a fly ball hit by Johnny Damon before committing an error.

[citation needed] He was selected as the Red Sox most valuable player (winner of the 2009 Thomas A. Yawkey Memorial Award) in voting by the Boston Chapter of the Baseball Writers' Association of America.

[145][146] In the seventh inning of that day's game, Ben Cherington, the Red Sox General Manager, informed Valentine that a transaction was pending.

Youkilis hit a triple in his last at bat, and received a long standing ovation while tipping his helmet to the crowd after being taken out for pinch runner Nick Punto.

On July 9, 2012, Youkilis was named the American League Player of the Week, after batting .478 with three home runs and 10 RBI in a 5–1 span for the White Sox.

During his first at bat, the Fenway Park crowd gave him a loud, extended cheer, causing Youkilis to step out of the batter's box and acknowledge fans.

[172] Michael Lewis's 2003 best-seller Moneyball: The Art of Winning an Unfair Game focuses on Oakland Athletics' General Manager Billy Beane's use of Sabermetrics as a tool in the evaluation of potential prospects.

In Jews and Baseball: An American Love Story, a 2010 documentary film narrated by Dustin Hoffman, Youkilis noted:It's something that I probably won’t realize until my career is over, how many people are really rooting for me and cheering for me.

[192][193][194] However, Youkilis, sensitized by the fact that he is Jewish, declined to be associated with late Cincinnati Reds owner Marge Schott, who was known for her racist and anti-Semitic statements.

Youkilis's foundation focuses on raising support and awareness for the health, advocacy, safety, and medical healing of children across Massachusetts, in his hometown of Cincinnati, and beyond.

Rallying the support of volunteers, local business, and the heart of Red Sox Nation, Kevin Youkilis Hits for Kids teams with existing, community-based children's charities and medical research efforts that lack sufficient funding and awareness.

The episode was recorded at Boston's Eagle's Deli and featured Youkilis rooting against host (and New York Yankees fan) Adam Richman in an eating challenge.