The First Battle of Algeciras was a naval battle fought on 6 July 1801 between a squadron of British Royal Navy ships of the line and a smaller French Navy squadron at anchor in the fortified Spanish port of Algeciras in the Strait of Gibraltar. The British outnumbered their opponents, but the French position was protected by Spanish gun batteries and the complicated shoals that obscured the entrance to Algeciras Bay. The French squadron, under Contre-Amiral Charles Linois, had stopped at Algeciras en route to the major Spanish naval base at Cadiz, where they were to form a combined French and Spanish fleet for operations against Britain and its allies in the French Revolutionary Wars. The British, under Rear-Admiral Sir James Saumarez, sought to eliminate the French squadron before it could reach Cadiz and form a force powerful enough to overwhelm Saumarez and launch attacks against British forces in the Mediterranean Sea.

Vice-Admiral Count Pierre Étienne René Marie Dumanoir Le Pelley was a French Navy officer, best known for commanding the vanguard of the French fleet at the Battle of Trafalgar. His conduct during this battle was the subject of controversy.