PA 329 was originally designated in 1928 to run from Egypt south to U.S. Route 22 (US 22), US 309, PA 29, and PA 43 in Center City Allentown while the alignment between Cementon and Bath was designated as part of PA 145 in 1928. By 1940, the route was realigned to a new alignment in Whitehall Township. In 1941, PA 145 and PA 329 switched alignments, with PA 329 heading east to PA 45 (now PA 248) and PA 987 in Bath and PA 145 heading south to US 22, US 309, and PA 29 in Allentown. PA 329 was also extended west to US 309 (now PA 873) in Neffs and a branch of the route was designated between Balliettsville and US 309/PA 29 and US 309 Byp. at the northern edge of Allentown. The section of PA 329 between Balliettsville and Allentown was decommissioned by 1950.