Polylactide (PLA) is a bioderived and biodegradable polyester that suffers from low crystallinity and slow crystallization kinetics. In this work, a fully bio-based nucleating agent (biofiller) has been developed from cross-linked PLA. The impact of the biofiller (BF) particles on PLA crystallinity, crystallization kinetics and mechanical properties was investigated using Differential Scanning Calorimetry (DSC) and flexural tests. Unlike neat PLA, the nucleated samples had a distinct crystallization peak, whereas cold crystallization was not observed. Upon addition of the 5 wt% of BF, a maximum PLA crystallinity of 20% was achieved. The crystallinity of the nucleated samples increased to 55% after 2 min annealing at 100°C, and the flexural modulus increased by 25%. Furthermore, incorporation of the BF into PLA accelerated the crystallization kinetics significantly. The improvements in the thermal and mechanical properties were attributed to the exceptional nucleating capacity of the BF, resulting from its compatibility with the matrix. Additionally, hydrolytic degradation experiments revealed that PLA degradation was not compromised upon addition of the BF, suggesting that the PLA maintained its inherent biodegradation properties.