Tony Marnell (b. 1949) is one of the most influential figures in modern casino design and construction, and is best known as the founder, chief executive, and chairman of the board of Marnell Corrao Associates.

Marnell graduated from the University of Southern California in 1972 with a B.A. in Architecture before working in several architectural and construction firms. He joined Corrao construction in 1974 and, after Lud Corrao's 1982 retirement, reconstituted the firm as Marnell Corrao Associates.

After forming MCA, Marnell helped build several of today's best known casinos, including Mirage, Treasure Island, Bellagio, Wynn Las Vegas, several Caesars Palace expansion projects including the Forum Shops, Harrah's New Orleans, Harrah's Atlantic City (expansion), and the Borgata. MCA has also designed all five custom Cirque du Soleil theaters currently open on the Las Vegas Strip and several other retail, entertainment, and convention facilities.

Marnell also built and operated the Rio All Suite Hotel and Casino on Flamingo Road in Las Vegas, serving as CEO from before its 1990 opening to its 1999 acquisition by Harrah's Entertainment.

Marnelll is a registered architect in several states and is currently certified by the National Council of Architectural Registration Boards. He is also an honorary member of AIA (American Institute of Architects), Trustee Emeritus of the University of Nevada Las Vegas Foundation Board, a member of the USC Board of Councilors, a member of Duck's Unlimited and the National Italian American Foundation.