If elected, he promised to create jobs in the city and help businesses succeed.
Catsimatidis is best known for owning the grocery store chain as well as real estate and oil companies. Forbes ranked Catsimatidis No. 132 on the magazine's 400 List, and estimated his worth at $3 billion.
Catsimatidis had pledged to spend $20 million of his own money on the campaign, but toned down his prediction at Tuesday's news conference.
Dan Isaacs, chairman of the New York Republican County Committee, called Catsimatidis "a quintessential New Yorker" with an "only in America story."
Catsimatidis, born in Greece, immigrated with his parents to New York in 1949. He grew up on 135th Street in Harlem and graduated from New York public schools. He attended New York University, but was eight credits shy of graduating. He then bought the grocery store he worked in as a teen and built up the chain.