The authors have observed the condensation of fermionic atom pairs in the BCS-BEC crossover regime using a trapped gas of ${}^{40}$K atoms. They evaporatively cooled the gas to quantum degeneracy and used a magnetic-field Feshbach resonance to control atom-atom interactions. The resonance position was determined from low-density measurements of molecule dissociation. To search for condensation on both sides of the resonance, they introduced a technique to pairwise project fermionic atoms onto molecules, enabling the measurement of the momentum distribution of fermionic atom pairs. The transition to condensation was mapped as a function of the initial atom gas temperature $T$ compared to the Fermi temperature $T_F$ for magnetic-field detunings on both the BCS and BEC sides of the resonance. The study demonstrates that condensation of fermionic atom pairs occurs in the BCS-BEC crossover regime, with the condensed state having a significantly longer lifetime compared to the BEC limit. This experimental realization follows over two decades of theoretical investigation and marks the beginning of experimental study of this physics.The authors have observed the condensation of fermionic atom pairs in the BCS-BEC crossover regime using a trapped gas of ${}^{40}$K atoms. They evaporatively cooled the gas to quantum degeneracy and used a magnetic-field Feshbach resonance to control atom-atom interactions. The resonance position was determined from low-density measurements of molecule dissociation. To search for condensation on both sides of the resonance, they introduced a technique to pairwise project fermionic atoms onto molecules, enabling the measurement of the momentum distribution of fermionic atom pairs. The transition to condensation was mapped as a function of the initial atom gas temperature $T$ compared to the Fermi temperature $T_F$ for magnetic-field detunings on both the BCS and BEC sides of the resonance. The study demonstrates that condensation of fermionic atom pairs occurs in the BCS-BEC crossover regime, with the condensed state having a significantly longer lifetime compared to the BEC limit. This experimental realization follows over two decades of theoretical investigation and marks the beginning of experimental study of this physics.