The club captain was included in Ronald Koeman's staring line-up for Sunday's LaLiga clash with Real Sociedad, taking him to 768 games for the club he first joined as a 12-year-old.
Messi equaled the previous record, held by former teammate Xavi, in Monday's 3-0 win over Huesca clash.
The 33-year-old and Xavi are the only players in the club's history to have surpassed 700 games for the Catalans, with Andres Iniesta next on the all-time appearance list on 674.
Messi already boasts the record for the most trophies won (34) and highest goal tally (658) for Barca, and marked the record-equalling appearance in typical style, netting a sensational opener before laying on an assist and then rounding off the scoring himself in a 4-1 victory.
He also became the first player to score 20 or more goals in 13 successive LaLiga campaigns in the process and, on Sunday, he took the outright record for Barca appearances when he started against Real Sociedad.
To date, Messi has featured in 511 LaLiga matches, while playing 149 Champions League fixtures, 79 Copa del Rey games, 20 in the Supercopa de Espana, five in the Club World Cup and four in the UEFA Super Cup.
Messi tops LaLiga's goalscoring charts this season with 21 goals, as Barca look to close within four points of leaders Atletico Madrid, who beat Deportivo Alaves 1-0.
The Argentina great has been involved in 21 goals in 22 games against La Real in LaLiga (14 goals and seven assists), scoring and or assisting in 14 of them.
Barca have won their last eight games away from home in LaLiga, keeping six clean sheets. They could level their third-best consecutive winning run on the road, and would only be behind their 12 wins in a row between May 2010 and January 2011 and 10 between August 2012 and January 2013.
Messi has yet to sign a new contract with Barca which means, as it stands, he may be down to his last 11 games in all competitions with the club following Sunday's meeting with La Real.
Ronald Koeman's team have 10 LaLiga fixtures remaining following the international break, while they will also take on Athletic Bilbao in the Copa del Rey final next month.