Thaddeus John Kwalick (born April 15, 1947) is a former American football tight end in the National Football League and World Football League. He played for the San Francisco 49ers from 1969-1974 and the Oakland Raiders from 1975-1977. In 1975 he also played with the Philadelphia Bell of the World Football League. He attended Penn State University after growing up and playing high school football at Montour High School outside of Pittsburgh.
Kwalick made several All-America teams in 1967, and was unanimous in 1968, becoming Penn State's first two-time All-America. His career totals, 1343 yards and 10 touchdowns, were Penn State records for a tight end. He was inducted into the College Football Hall of Fame in 1989 and National Polish-American Sports Hall of Fame in 2005.
Kwalick scored the first touchdown in Candlestick Park in 1971.
Kwalick earned a Bachelor of Science in Physical Education from Penn State University in 1969. He is the president/owner of ProTech Voltage Systems, Inc., in Santa Clara, California. He is of a Polish descent.