The extraction process is an important step that is widely used in food, agriculture, cosmetics, pharmaceuticals, modern and alternative medicine, etc. Because of plants contain low amount of beneficial phytochemicals, obtaining high amounts of the desired compound is important in terms of extraction efficiency. In recent years, modern and green technologies have become more important; they also bring advantages such as high selectivity, less solvent, time, and energy requirements. Apigenin (4′, 5, 7-trihydroxyflavone), a naturally occurring flavonoid, possesses a variety of pharmaceutical properties such as anticancer, anti-inflammatory, and antioxidant properties which are very important for human health. Parsley is one of the most common herbs used in cuisines and is known as the best source of apigenin. Therefore, this study aimed to investigate the effects of various extraction methods on the extraction of biologically active compounds from parsley leaves. Conventional (maceration), ultrasound-assisted extraction (UAE), and ohmic heating extraction (OHE) methods were compared in terms of yield, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities, and apigenin quantities. The results showed that the UAE and OHE techniques had higher extraction efficiency than the maceration method. UAE achieved satisfactory extraction efficiency, shorter processing time, high energy savings, and retention of heat-labile compounds. OHE, as an advanced heating technology, increased the permeability of cell membranes, facilitating the release of bioactive compounds. The results revealed that the OHE technique was the most effective method for apigenin extraction (159.63 ppb) and antioxidant activity.