State Road 104 (SR 104), locally known as Dunn Avenue, is a 7.6-mile-long (12.2 km) state highway that travels through the northern part of Jacksonville in the northeastern part of the U.S. state of Florida.

SR 104 begins at the intersection of Dunn Avenue and US 1/US 23, where SR 104 takes Dunn Avenue eastward into sparsely-populated residential portions of Jacksonville.

East of the interchange with Interstate 295 (I-295), development becomes more frequent, with woodlands still bordering some portions of the road.

SR 104 has an interchange with I-95, continuing east onto Busch Drive towards its eastern terminus of US 17, where former SR 163 used to continue to the east.

[2] The entire route is in Jacksonville, Duval County.