Lucas Tanner is an NBC television drama that aired during the 1974-75 season. The title character, played by David Hartman, was a former baseball player and sportswriter who becomes an English teacher at the fictional Harry S Truman High School in Webster Groves, Missouri, a suburb of St. Louis. Episodes often deal with the resistance of traditional teachers to Tanner's unorthodox teaching style.

Regular co-stars included Rosemary Murphy, Kimberly Beck, and ten-year-old Robbie Rist. Unusually, the show was actually filmed in Webster Groves, rather than on a Hollywood backlot. That gave it a somewhat unusual "look" for a prime-time TV series.

A 90-minute pilot film of the series aired on NBC the week of May 4, 1974; the pilot also starred Kathleen Quinlan and Joe Garagiola.

This series was Hartman's last television series as an actor—in November 1975, he began a long-running stint as co-host of ABC's Good Morning America.