Roosevelt decisively carried New Jersey with 59.54% of the vote to Landon's 39.57%, a victory margin of 19.97%. 
Reflecting the decisiveness of his statewide victory, Roosevelt swept 17 of the New Jersey's 21 counties with majorities of the vote, breaking 60% of the vote in 5 of them. This result represented dramatic gains from 1932, when Roosevelt had narrowly carried the state by less than 2 points while winning only 4 counties in the state. In 1932, Roosevelt had won majorities in populous Middlesex County and rural Warren County, along with a plurality win in Passaic County, but much of Roosevelt's margin of victory was provided by a landslide win in heavily populated Hudson County. Roosevelt had received more than 70% of the vote in Hudson County, part of the New York City metro area, in 1932. In 1936, Roosevelt again broke 70% of the vote in Hudson County, but this time 13 other counties flipped from voting for Herbert Hoover in 1932 to Roosevelt in 1936, enabling him to win the state with a much more comfortable 20 point margin.
In North Jersey, Roosevelt won all but 2 out of the 10 northernmost counties. Besides his landslide win in Hudson County, Roosevelt also received more than 60% of the vote in Middlesex and Mercer Counties and won majorities in seven other counties. Landon won only rural Sussex County along with Morris County.
Roosevelt decisively swept South Jersey, winning majorities in all seven out of seven of the southernmost counties in the state.
New Jersey in the early decades of the 20th century had been a reliably Republican state; prior to FDR's 1936 victory, the state had not given a majority of the vote to a Democratic presidential candidate since 1892, with FDR only winning the state with a bare plurality in 1932. (In 1912, Woodrow Wilson, then the sitting Governor of New Jersey, won the state's electoral votes, but with a plurality of only 41% in a 3-way race against a split Republican field, with former Republican President Theodore Roosevelt running as a third party candidate against incumbent Republican President William Howard Taft. Wilson lost the state to the GOP by a decisive 12-point margin in a head-to-head match-up in 1916.) The state's strong Republican lean was still evident in FDR's initial 1932 election campaign: although that year he narrowly won the state with a 49.5-47.6 plurality over Herbert Hoover, in the midst of his nationwide landslide, that still made the state almost 16% more Republican than the nation. In 1936, with the emergence of the New Deal Coalition, FDR made dramatic gains for the Democratic Party in New Jersey that would endure and transform it into a closely divided swing state with only a slight Republican lean, a pattern that would endure for much of the 20th century until New Jersey ultimately became a solid Democratic state in the 1990s. The 1936 election would be the first of many elections to conform to that pattern, with the results making the state about 4% more Republican than the nation.