Accurate crop yield estimation is paramount in agricultural monitoring and food security. In this study, we present a comprehensive investigation into estimating winter wheat yield in the Qazvin plane of Iran, leveraging the synergy between machine learning algorithms and the fusion of remote sensing data from radar and optical satellite sensors. The research is based on the availability of high-quality in situ yield data gathered by the Ministry of Agriculture in collaboration with the Food and Agriculture Organization (FAO), collected during the 2019-2020 crop year. The study area encompasses the Qazvin plane, an agriculturally significant region renowned for winter wheat production in Iran. In-situ data from various agricultural fields and seed types as reference measurements enabled us to conduct rigorous validation of the performance of machine learning algorithms and the effectiveness of the fused remote sensing data. The primary objective of this study is to assess and compare the performance of seven prominent machine learning algorithms for accurate estimation of the annual winter wheat yields. Additionally, we explored the potential of a proposed deep convolutional neural network (CNN) as a state-of-the-art approach for crop yield estimation, leveraging its ability to extract intricate spatial and spectral features from the remote sensing data. Through rigorous analysis of the pixel-level confusion matrices, we identify the most effective model for yield estimation, evaluating the complementarity and information redundancy between the two types of remote sensing data. In this study, we conducted an extensive comparison of various machine learning algorithms for winter wheat crop yield estimation. Among the four best-performing algorithms examined, namely polynomial regression (RMSE = 0.5657), random forest (RMSE = 0.1632), XGBoost (RMSE = 0.3153), and the proposed deep convolutional neural network (CNN) (RMSE = 0.1324), the CNN demonstrated superior performance. The CNN's yield estimation exceeded the total yearly agricultural statistics of Qazvin by 0.03 percent. However, this discrepancy can be attributed to various factors, including errors in wheat and barley fields mapping , mis-calculation in statistics, and the inherent limitations of yield estimation algorithms in capturing the dynamic nature of agricultural systems. The findings of this research provide valuable insights into the potential of machine learning algorithms and remote sensing data fusion for accurate crop yield estimation, paving the way for enhanced agricultural monitoring and decision-making processes in the region.