Asa Packer (December 29, 1805 – May 17, 1879) was an American businessman who pioneered railroad construction, was active in Pennsylvania politics, and founded Lehigh University in Bethlehem, Pennsylvania. He was a conservative and religious man who reflected the image of the typical Connecticut Yankee. He served two terms in the United States House of Representatives from 1853 to 1857.

Packer was born in Mystic, Connecticut in 1805 and moved to Pennsylvania, where he became a carpenter's apprentice to his cousin Edward Packer in Brooklyn Township, Pennsylvania. He also worked seasonally as a carpenter in New York City and later in Springville Township, Pennsylvania, where he met his wife Sarah Minerva Blakslee.

Packer and his wife settled on a farm. In the winter months, he went to Tunkhannock, Pennsylvania on the Susquehanna River and used his skill in carpentry to build and repair canal boats. This continued for 11 years. In 1833, Packer settled in Mauch Chunk in present-day Jim Thorpe, Pennsylvania, where he became the owner of a canal boat, which transported anthracite coal from Pennsylvania's Coal Region to Philadelphia. He then established A. & R. W. Packer, a firm that built canal boats and locks for the Lehigh Coal & Navigation Company.

Packer urged the Lehigh Coal & Navigation Company to adopt a steam railway as a coal carrier, but the project was not then considered feasible. In 1851, he became the major stockholder of the Delaware, Lehigh, Schuylkill & Susquehanna Railroad Company, which became the Lehigh Valley Railroad in January 1853, and they built a railway line from Mauch Chunk to Easton between November 1852 and September 1855. Construction commenced on the Mauch Chunk-Easton line just as Packer's five year charter was to expire. He built railways connecting the main line with coal mines in Luzerne and Schuylkill counties, and he planned and built the extension of the line into the Susquehanna Valley and thence into New York state to connect at Waverly with the Erie Railroad. Among his clerks and associates during this period was future businessman and soldier George Washington Helme.

Packer also took an active part in politics. In 1842 and 1843, he was a member of the Pennsylvania House of Representatives. In 1843 and 1844, he was county judge in Carbon County under Governor David R. Porter.

He served two terms as a Democratic member of the U.S. House of Representatives beginning in 1853.

George Washington Woodward at the 1868 Democratic National Convention entered Packer's name as a candidate for President as a Favorite son despite himself not being present or actively campaigning. Packer earned a nearly consistent 26 delegates through the 14th round of the ballot and due to him being little known outside of Pennsylvania, with the statement from one delegate; "Who in the hell is Packer?" being used as the headline for many New York journalists, who started to see Packer as an unoffensive moderate candidate that could increase the Democratic party's electability. However, the convention instead went with Horatio Seymour, for largely the same reason but also due to Seymour's name recognition. Interestingly, Woodward attempted to forge a Packer - Blair ticket, however, Francis Preston Blair Jr. was instead named Seymour's running-mate. Packer made an unsuccessful bid for the Democratic Party's Presidential nomination in 1868.

He got the party's nod for the 1869 Pennsylvania Governor's race, but lost the campaign to John W. Geary by 4,596 votes, one of the closest statewide races in Pennsylvania history.