Ellis attended Ottawa Hills High School in Grand Rapids, Michigan, where he starred in baseball and American football. Drafted by the San Francisco Giants in 1968, he did not sign, as he hoped for a team that would promote him to the major leagues quickly. Ellis then attended Michigan State University, where he played college baseball for the Michigan State Spartans baseball team. Ellis batted.380 as a sophomore and.431 as a junior. He set Spartans single-season records with 14 home runs, 60 hits, 13 doubles, and 123 total bases. Ellis was voted college player of the year in 1971 by The Sporting News. Ellis was named to the All-American squad that same year. The Washington Senators were expected to choose Ellis with the first overall selection in the June 1971 secondary draft. Instead, the Senators chose pitcher Pete Broberg. After the Chicago Cubs selected Burt Hooton with the second pick, the Milwaukee Brewers drafted Ellis with the third selection. The Brewers immediately promoted him to the majors, bypassing minor league baseball. Ellis was the fourth player to go straight to the Major Leagues after being drafted without spending a day in the minors. The Brewers sold Mike Hegan to the Oakland Athletics, naming Ellis their starting first baseman. The Brewers expected success from Ellis, comparing him to Chris Chambliss. This turned out to be premature, as Ellis batted just.198 in 36 games that year and was sent to the minors. The Brewers demoted Ellis to the Evansville Triplets of the Class AAAAmerican Association, where he batted.300. In 1972, Ellis played for the San Antonio Brewers of the Class AATexas League and Evansville. He spent all of the 1973 season with Evansville. Ellis began the 1974 season with the Brewers. Despite hitting.298 in 47 at-bats, the second bestbatting average on the team, the Brewers demoted Ellis to the Sacramento Solons of the Class AAA Pacific Coast League in June, when they acquired Deron Johnson from the Oakland Athletics. Ellis batted.296 for the Solons in 1974. In 1975, Ellis suffered an arm injury in spring training, and the Brewers returned him to Sacramento. Ellis spent all of the 1975 season with the Solons, with the exception of six games played with Milwaukee. Ellis batted.250 with the Solons in 1975. After the 1975 season, Ellis took out an advertisement in The Sacramento Union apologizing to the fans of Sacramento for his low batting average. Ellis remained with Brewers' affiliates, playing for the Spokane Indians of the PCL in 1976 and 1977. A free agent after the 1977 season, Ellis signed with the Cleveland Indians organization for the 1978 season, and played for the Portland Beavers in 1978 and Tacoma Tugs in 1979, both in the PCL. He was sold to the Pittsburgh Pirates during the 1979 season, who assigned him to Portland for the remainder of the 1979 season, and for 1980.
Ellis has a master's degree in psychology. Ellis wrote an autobiographical book, titled The Outfielder, which was not published. He also wrote a screenplay, titled The Tundra Ghost, which was inspired by his time as an extra on The Slugger's Wife. With Mike Schmidt, Ellis co-wrote "The Mike Schmidt Study, Hitting Theory, Skills and Technique".
