When Matt and Foggy talk about the language classes they are taking in college, Foggy claims that Matt only took Spanish to get close to a Greek girl that was in the same class. This is a reference to Elektra Natchios, who in the comics was one of Matt's many love interests and also a ninja assassin.
During the flashback to Foggy and Matt's early law practising days, they are seen representing a company called Roxxon Energy Corporation. In the Marvel comics universe Roxxon often appears as a morally questionable company that is sometimes engaged in illegal activities.
The roof-top park where Fisk (Vincent D'Onofrio) meets with Madam Gao (Wai Ching Ho) is the same park where Spider-Man dropped off Mary Jane Watson after rescuing her during the Green Goblin's first attack in Spider-Man (2002).
The fundraising event was being held in a building owned by an astrological believer and real estate owner called Van Lunt. This is a reference to Cornelius Van Lunt, who in the Marvel Universe (comics) went on to form the original crime syndicate Zodiac and became the supervillain Taurus.
In Ben Urich's office, headlines can be seen referencing events in Harlem in The Incredible Hulk (2008) and the battle of New York in The Avengers (2012).