Lazaro Alonso (born March 25, 1974) is a Cuban-American actor. He is known for playing Tsu'tey in James Cameron's science fiction film Avatar and Fenix Calderon in the film Fast & Furious. Alonso has had roles in other films such as Jarhead, This Christmas, Miracle at St. Anna and Detroit. Since 2019, Alonso is part of the main cast of the series The Boys (based on the comic book series of the same name) playing the character known as Marvin T. "MM (Mother's Milk)" Milk.

Alonso was born and raised in Washington, D.C. to Cuban immigrant parents. He grew up in Mount Pleasant and graduated from St. John's College High School. He is an alumnus of Howard University. After graduating from Howard University with a BBA in marketing, he had a career as an investment banker at Merrill Lynch on Wall Street before making his way into entertainment.

Alonso began his career hosting the television shows A.M. @BET and NYLA. Alonso has also appeared in music videos by recording artists Toni Braxton and Aaliyah.

Alonso has had supporting roles in films such as Stomp the Yard, Down for Life, Jarhead, G, Leprechaun: Back 2 tha Hood, This Christmas and Miracle at St. Anna.

In 2009, he played Fenix Calderon, the main antagonist in the film Fast & Furious, the fourth installment in the Fast & Furious film series. Alonso had a major role as the Na'vi warrior Tsu'tey in James Cameron's science fiction adventure film Avatar.

Alonso played one of the lead characters on the 2011, TV series Breakout Kings during its first season and the first episode of season two.

He has made television guest starring appearances on The Unit, Bones, CSI: Miami, NCIS, The Practice and Eyes.

Alonso was the lead in the 2013, NBC drama Deception.