The 2021 Appalachian State Mountaineers baseball team represented Appalachian State University during the 2021 NCAA Division I baseball season.

The Mountaineers played their home games at Beaver Field at Jim and Bettie Smith Stadium and were led by fifth-year head coach Kermit Smith.

Source:[2] The Sun Belt Conference Coaches Poll was released on February 15, 2021 and the Mountaineers were picked to finish fifth in the East Division with 21 votes.

[3] Source:[4] Pitchers Catchers Infielders Outfielders Utility *Rankings are based on the team's current ranking in the D1Baseball poll.

References:[6] ^ Collegiate Baseball ranked 40 teams in their preseason poll, but only ranked 30 teams weekly during the season.† NCBWA ranks 35 teams in their preseason poll, but only ranks 30 teams weekly during the season.