The 1870 United States House of Representatives elections in South Carolina were held on November 1, 1870, to select six Representatives for two-year terms from the state of South Carolina. The fifth and sixth seats were decided by an at-large election, but the House of Representatives refused to seat the two winners. The two incumbents who ran were re-elected and the two open seats were retained by the Republicans. The composition of the state delegation thus remained solely Republican.
The seat for the 1st congressional district became vacant following the resignation of Republican Benjamin F. Whittemore in February 1870. A special election was called to be held simultaneously with the regular election and Republican Joseph Rainey defeated Democrat C.W. Dudley to serve the remainder of the term for the 41st Congress.
|-| | colspan=5 |Republican hold|-
Republican Joseph Rainey defeated Democrat C.W. Dudley in the regular election for the 1st congressional district to win the term for the 42nd Congress.
|-| | colspan=5 |Republican hold|-
Incumbent Republican Congressman Christopher C. Bowen of the 2nd congressional district, in office since 1868, was defeated by black Republican Robert C. De Large in the general election.
|-| style="color:inherit;background:#ff00ff" || Union Reform| Robert Seymour Symmes Tharin| align="right" | 862| align="right" | 2.6| align="right" | |-|-| | colspan=5 |Republican hold|-
Incumbent Republican Congressman Solomon L. Hoge of the 3rd congressional district, in office since 1869, declined to run for re-election. Robert B. Elliott was nominated by the Republicans and defeated Union Reform challenger John E. Bacon in the general election.
|-| style="color:inherit;background:#ff00ff" || Union Reform| John E. Bacon| align="right" | 13,997| align="right" | 40.5| align="right" | |-|-| | colspan=5 |Republican hold|-
Incumbent Republican Congressman Alexander S. Wallace of the 4th congressional district, in office since 1870, defeated Democratic challenger Isaac G. McKissick.
|-| | colspan=5 |Republican hold|-
The state believed that it was entitled to two additional seats in the House of Representatives and elected these members from an At-large congressional district. The voters voted for two candidates and the top two vote getters would be sent to Washington, but there were only two candidates running in the at-large election. White Republican J. P. M. Epping and black Republican Lucius Wimbush won the election, but the House of Representatives refused to seat them.
|-| | colspan=5 |Republican win|-