The 2013–14 season was Olympiacos's 55th consecutive season in the Super League Greece and their 88th year in existence. Olympiacos also participated in the Greek cup and 2013–14 UEFA Champions League group stage. The first game of the season took place at OAKA on 19 August against AEL Kalloni.
Olympiacos won the domestic title for the fourth year in a row, breaking the all-time record for the biggest point difference between the first and the second team in the regular season. The most memorable accomplishment of the year was arguably the 2–0 win over Manchester United in the first leg of the round of 16 of the Champions League, though not managing to defend that score in England.
At the domestic cup, Olympiacos was eliminated in the semifinals by PAOK 2–2 on aggregate, falling off of the away goals rule.
Olympiacos' top goalscorer for the season was striker Kostas Mitroglou, who moved to Fulham at the end of the January 2014 transfer window for a fee of approximately €15 million.
"Squad at end of season"
Players.
First-team squad.
 ;templatestyles src="Template:Football squad player/styles.css" / ;
Out on loan.
 ;templatestyles src="Template:Football squad player/styles.css" / ;
Olympiacos U20 squad.
Olympiacos U20 is the youth team of Olympiacos. They participate in the Super League U20 championship and in UEFA Youth League competition. They play their home games at the 3,000-seater Renti Training Centre in Renti, Piraeus.
 ;templatestyles src="Template:Football squad player/styles.css" / ;
Pre-season and friendlies.
 ;templatestyles src="Legend/styles.css" / ;  Win
 ;templatestyles src="Legend/styles.css" / ;  Draw
 ;templatestyles src="Legend/styles.css" / ;  Loss
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
Competitions.
Super League Greece.
Matches.
 ;templatestyles src="Legend/styles.css" / ;  Win
 ;templatestyles src="Legend/styles.css" / ;  Draw
 ;templatestyles src="Legend/styles.css" / ;  Loss
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
Greek Football Cup.
Second round.
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
Third round.
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
Quarter-finals.
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
Semi-finals.
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
UEFA Champions League.
Group stage.
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
Knockout phase.
Round of 16.
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
 ;templatestyles src="Template:Football_box_collapsible/styles.css" / ;
References.
 ;templatestyles src="Reflist/styles.css" / ;