The 1998 Arizona Diamondbacks season was the franchise's 1st season in Major League Baseball and their 1st season at Chase Field in Phoenix, Arizona, as members of the National League West. They looked to contend in what was a strong National League West. They finished the season 33 games behind the National League Champion San Diego Padres with a record of 65–97, last in the division. Jeff Suppan was the last player from the inaugural team still active in Major League Baseball when he retired in 2012.

Offseason

Expansion Draft

Round 1

Round 2

Round 3

1996–97 MLB June drafts and minor league affiliates

The two expansion teams set to debut in 1998, the Diamondbacks and Tampa Bay Devil Rays, had two full seasons to establish scouting and player development systems and were permitted to participate fully in the 1996 and 1997 Major League Baseball drafts. The Diamondbacks drafted 30th in both 1996 and 1997, selecting 62 players (1996) and 60 players (1997) in those drafts. The team began developing those players in a farm system with three minor-league affiliates in 1996 and four in 1997. Among the players selected and signed by Arizona from those drafts were pitchers Brad Penny (fifth round, 1996) and Casey Fossum (seventh, 1996); infielders Alex Cintrón (36th, 1997), Jack Cust (first, 1997) and Junior Spivey (36th round, 1996); and outfielders Ron Calloway (eighth, 1997) and Jason Conti (32nd, 1996).

1996 farm system

Visalia affiliation shared with Detroit Tigers

1997 farm system

LEAGUE CHAMPIONS: High Desert

Regular season

Opening Day starters

Season standings

Record vs. opponents

Notable transactions

Roster

Game log

Player stats

Batting

Starters by position

''Note: Pos = Position; G = Games played; AB = At bats; H = Hits; HR = Home runs; RBI = Runs batted in; Avg. = Batting average''

Other batters

''Note: G = Games played; AB = At bats; H = Hits; HR = Home runs; RBI = Runs batted in; Avg. = Batting average''

Pitching

Starting pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts; BB = Walks allowed

Other pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts; BB = Walks allowed

Relief pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; SV = Saves; ERA = Earned run average; SO = Strikeouts; BB = Walks allowed

Farm system