The paper explores the use of quantum discord to characterize nonclassical correlations in the DQC1 quantum computational model, which involves a single control qubit and a collection of qubits in a completely mixed state. Although there is no entanglement between the control qubit and the mixed qubits, the quantum discord across this split is nonzero for typical instances of the DQC1 circuit, indicating the presence of nonclassical correlations. Quantum discord is proposed as a figure of merit for characterizing the resources in this computational model. Quantum discord measures nonclassical correlations, including but not limited to entanglement. It is defined as the difference between mutual information and a quantum version of classical mutual information. The paper shows that even in the absence of entanglement, the DQC1 circuit exhibits nonclassical correlations, as measured by quantum discord. This suggests that quantum discord may be a better measure of quantum resources than entanglement for certain purposes. The DQC1 circuit efficiently evaluates the normalized trace of a unitary matrix. The control qubit is completely separable from the mixed qubits, and the final state has vanishingly small entanglement. However, the quantum discord between the control qubit and the mixed qubits is nonzero, indicating nonclassical correlations. The paper provides an analytical expression for the quantum discord in the DQC1 circuit and compares it with numerical results for a circuit with five qubits. The analytical expression is found to be accurate even for small n. The paper also discusses the limitations of entanglement detection in the DQC1 circuit and shows that quantum discord is the first signature of nonclassical correlations in this model for α ≤ 1/2. The results suggest that nonclassical correlations, as quantified by quantum discord, may explain the speed-up in the DQC1 circuit and potentially in other quantum computational circuits. Quantum discord is a true measure of nonclassical correlations and works well for both pure- and mixed-state quantum computation.The paper explores the use of quantum discord to characterize nonclassical correlations in the DQC1 quantum computational model, which involves a single control qubit and a collection of qubits in a completely mixed state. Although there is no entanglement between the control qubit and the mixed qubits, the quantum discord across this split is nonzero for typical instances of the DQC1 circuit, indicating the presence of nonclassical correlations. Quantum discord is proposed as a figure of merit for characterizing the resources in this computational model. Quantum discord measures nonclassical correlations, including but not limited to entanglement. It is defined as the difference between mutual information and a quantum version of classical mutual information. The paper shows that even in the absence of entanglement, the DQC1 circuit exhibits nonclassical correlations, as measured by quantum discord. This suggests that quantum discord may be a better measure of quantum resources than entanglement for certain purposes. The DQC1 circuit efficiently evaluates the normalized trace of a unitary matrix. The control qubit is completely separable from the mixed qubits, and the final state has vanishingly small entanglement. However, the quantum discord between the control qubit and the mixed qubits is nonzero, indicating nonclassical correlations. The paper provides an analytical expression for the quantum discord in the DQC1 circuit and compares it with numerical results for a circuit with five qubits. The analytical expression is found to be accurate even for small n. The paper also discusses the limitations of entanglement detection in the DQC1 circuit and shows that quantum discord is the first signature of nonclassical correlations in this model for α ≤ 1/2. The results suggest that nonclassical correlations, as quantified by quantum discord, may explain the speed-up in the DQC1 circuit and potentially in other quantum computational circuits. Quantum discord is a true measure of nonclassical correlations and works well for both pure- and mixed-state quantum computation.