Using the monomer-dimer representation of strongly coupled U (N ) lattice gauge theories with staggered fermions, we study finite temperature chiral phase transitions in (2 + 1) dimensions. A new cluster algorithm allows us to compute monomer-monomer and dimer-dimer correlations at zero monomer density (chiral limit) accurately on large lattices. This makes it possible to show convincingly, for the first time, that these models undergo a finite temperature phase transition which belongs to the Kosterlitz-Thouless universality class. We find that this universality class is unaffected even in the large N limit. This shows that the mean field analysis often used in this limit breaks down in the critical region.Computing quantities in Lattice QCD with massless quarks is notoriously difficult. Most known algorithms break down in the chiral limit. For this reason questions related to the universality of chiral phase transitions are among the many questions that remain unanswered. It is often difficult to compute critical exponents sufficiently accurately to rule out all possibilities except one.The most useful simplification of lattice QCD occurs in the strong coupling limit which retains much of the underlying physics of QCD except for large lattice artifacts. In this limit spontaneous chiral symmetry breaking and its restoration due to finite temperature effects have been studied using large N and large d expansions [1][2][3]. However, since these approaches are based on mean field analysis they cannot help in determining the universality of phase transitions.Interestingly lattice QCD with staggered fermions interacting through U (N ) gauge fields can be mapped into a monomer-dimer system in the strong coupling limit [4]. These models contain an exact U (1) chiral symmetry, a remnant of the full chiral symmetry of QCD. When it was proposed, the monomer-dimer representation offered a new approach to study strongly coupled gauge theories close to the chiral limit from first principles. Unfortunately, this dream has remained unfulfilled until now. As in the weak coupling regime, most numerical simulations of the monomer-dimer systems have suffered from critical slowing down close to the chiral limit and hence have only allowed calculations with limited accuracy [5].Recently, a cluster algorithm has been discovered to study these strongly coupled lattice gauge theories in the chiral limit [6]. This allows precision calculations in the chiral limit for the first time. As a first application of this new algorithm, in this article we study the finite temperature critical behavior in (2 + 1) dimensions. In agreement with expectations from universality, we find with very high precision the chiral phase transition to be in the same universality class as the Berezinski-KosterlitzThouless (BKT) transition [7]. Our results are comparable to other known high precision spin-model studies of this universality class. We also show that the BKT transition persists even in the large N limit, showing that the mean field analysis breaks ...