Which twin played toddler Little Ricky along with Joe Mayer?

Mike Mayer played toddler Little Ricky alongside his twin brother Joe Mayer.

Little Ricky was played by several actors as the character grew from a baby into a school-age child. During the toddler period, twins Michael and Joseph Mayer shared the role, following a common television practice of using twins for demanding work with young children.

The brothers are often listed in different forms: Michael and Joseph Mayer in reference sources, and Mike and Joe Mayer in cast listings and trivia material. Thus, “Mike Mayer” is the commonly used short form of Michael Mayer. The question asks for the twin who appeared with Joe, making Mike the intended answer.

Little Ricky’s portrayal changed again later. Richard Keith, whose birth name was Keith Thibodeaux, played the older child and was also a talented drummer. Earlier performers included James John Ganzer and twins Richard and Ronald Lee Simmons. The character was the son of Lucy and Ricky Ricardo and became central to the show after his 1953 birth storyline.