DePaul University is a private Catholic research university in Chicago, Illinois, United States. Founded by the Vincentians in 1898, the university takes its name from the 17th-century French priest Saint Vincent de Paul. In 1998, it became the largest Catholic university in terms of enrollment in North America. Following in the footsteps of its founders, DePaul places special emphasis on recruiting first-generation students and others from disadvantaged backgrounds.

DePaul's two campuses are located in Lincoln Park and the Loop. DePaul is classified among "R2: Doctoral Universities – High research activity". The university enrolls around 14,500 undergraduates and about 7,900 graduate/law students. In 2017, about 90% of DePaul's students commuted or lived off campus. The student body represents a wide array of religious, ethnic, and geographic backgrounds, including over 118 foreign countries.

DePaul's intercollegiate athletic teams, known as the DePaul Blue Demons, compete in the Big East Conference. DePaul's men's basketball team has made 18 NCAA tournament appearances and appeared in two Final Fours. DePaul's softball team in 2019 had their third consecutive Big East Tournament title and 21st NCAA Tournament appearance in program history under head coach Tracie Adix-Zins.

Originally named St. Vincent's College, DePaul University was founded in 1898 by the Congregation of the Mission priests and brothers, known as the Vincentians. Followers of 17th-century French priest Saint Vincent de Paul, they founded the university to serve children of Catholic immigrants. Student enrollment grew from 70 in 1898 to 200 in 1903 in what is now the Lincoln Park neighborhood of Chicago.

In that year, James Quigley, Archbishop of Chicago, announced plans to create a preparatory seminary, now Archbishop Quigley Preparatory Seminary, for the archdiocese and allow the Jesuit Saint Ignatius College, now Loyola University Chicago to move its collegiate programs to the north side, threatening St. Vincent College's survival.

In response, the Vincentians re-chartered in 1907 as DePaul University, expressly offering all of its courses of study to men and women of any religious background. DePaul began admitting women in 1911 and awarded degrees to its first female graduates in 1912. It was one of the first Catholic universities to admit female students in a co-educational setting.

DePaul established the School of Music and the College of Commerce, the latter becoming one of the oldest business schools in the nation. In 1914, the college began offering courses in Chicago's Loop, the precursor of DePaul's second primary campus. In 1915, the Illinois College of Law completed its affiliation with the university and became the DePaul University College of Law. Enrollment totaled more than 1,100.

Although finances were rocky, the university continued to grow and build in the 1920s. In 1926, the university was first accredited by the North Central Association of Colleges and Universities. When DePaul's first sports teams were formed in the early 1900s, the monogram "D" was selected for the uniforms. From this originated the sports_nickname "D-men" which evolved into "Demons". The color blue, which signifies loyalty and was chosen in 1901 by a vote of the student body, was added to the name to create the "Blue Demons".