State Highway 43 is a Texas state highway that runs from Atlanta to Henderson.

SH 43 was originally proposed in 1919 to connect Longview to Rusk via Henderson. By 1922, the proposed route had been readjusted to extended farther west to Palestine and north to the Oklahoma border via Daingerfield. By 1933, the route had been further changed. The section from Henderson to Longview was transferred to SH 26, with the route now traveling northeast from Henderson to Marshall. The section southwest of Palestine to Round Rock, was renumbered from SH 43A. By 1935, the section from Round Rock to Palestine had been transferred to U.S. Highway 79.

SH 43A was originally designated by 1922 as an alternate route to SH 43, splitting in Kilgore and running southwest through Palestine to Round Rock. By 1933, the entire route had been transferred to the main route of SH 43.