Miller batted .276 with 32 home runs and 88 RBIs in 110 games for Triple-A Sacramento in 2011. The 26-year-old also appeared in seven games for the A's, going 3-for-12 with a home run.
"Jai Miller has the power, speed, basestealing skills and good athletic ability to be an asset in our outfield as he competes for a spot on our ballclub this spring," said Orioles executive vice president of baseball operations Dan Duquette.
Snyder, 25, had spent his entire career in the Baltimore organization since being drafted in the first round of the 2005 First-Year Player Draft.
Snyder has played primarily first base during his Minor League career, but he has also seen action at third base and served mostly as a catcher in his first two professional seasons.
Snyder spent most of last season at Triple-A Norfolk, hitting .261 with 14 home runs and 71 RBIs in 114 games. The right-handed-hitting Snyder played for the Major League club in each of the past two seasons, compiling a .273 (9-for-33) career batting average in 16 Major League contests.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time He also could be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.