Mexico is the Spanish-speaking country closest to the United States.
Assuming that by "Spanish speaking country" you mean a country where Spanish is the official language, Cuba is the closest to Florida.
Puerto Rico's closest Spanish-speaking neighbor is the Dominican Republic. The two countries are separated by the Mona Passage, which is approximately 50 miles wide at its narrowest point. Both share cultural and linguistic ties, as they are part of the Caribbean region.
Cuba is the closest spanish speaking country.
The Spanish-speaking country closest to Florida is Cuba. Cuba is located about 90 miles south of the southern tip of Florida.
Most probably, because Mexico is the closest neighbor to the United States, has friendly people and has a rich and varied culture. Also it is the country with most American expats in the world.
Our Spanish-speaking neighbor to the south is Mexico. It shares a long border with the United States and is known for its rich cultural heritage, diverse landscapes, and historical significance. Mexico is the most populous Spanish-speaking country in the world.
USA is the closest southern neighbor of Canada.
Cuba.
Cuba, roughly 90 miles south.
There is no country south of Spain that is "Spanish speaking" in North Africa. There is a minority of Moroccans who speak Spanish because of the previous colonization, but Spanish has minimal official or signage uses.
Cuba. It is 90 miles from the coast of the United States.