Pete O'Brien was a professional baseball player who played in the Major Leagues for over a decade. He was primarily a first baseman, but also played some outfield and designated hitter. O'Brien was known for his power hitting and solid defense.

O'Brien was born in California and attended college at Santa Clara University. He was drafted by the Texas Rangers in the second round of the 1982 MLB draft and made his Major League debut in 1983. O'Brien quickly established himself as a reliable hitter, batting over .300 in his first full season in 1984. He continued to be a consistent performer for the Rangers over the next several years, hitting over 20 home runs in four seasons and driving in over 90 runs three times.

In 1990, O'Brien was traded to the Cleveland Indians, where he played for two seasons. He had a solid year in 1991, hitting 20 home runs and driving in 75 runs. However, his production declined in 1992 and he was released by the Indians at the end of the season.

O'Brien signed with the Seattle Mariners for the 1993 season, but struggled at the plate and was released mid-season. He signed with the New York Yankees and played in 23 games for them before retiring at the end of the season.

Overall, O'Brien had a solid career in the Major Leagues, hitting .265 with 169 home runs and 682 RBIs. He was a two-time All-Star and won a Gold Glove award in 1988 for his defensive play at first base. After retiring from baseball, O'Brien worked as a hitting coach for several teams, including the Rangers and Yankees.