This book constitutes the thoroughly refereed proceedings of the Third Iberoamerican Conference, KGSWC 2021, held in Kingsville, Texas, USA, in November 2021.*The 22 full and 2 short papers presented were carefully reviewed and selected from 85 submissions.

InDO: The Institute Demographic Ontology.- Bridging Upper Ontology and Modular Ontology Modeling: A Tool and Evaluation.- Empirical Evaluation of a Cloud-based Graph Database: The case of Neptune.- Towards Knowledge Graphs Validation through Weighted Knowledge Sources.- Design and Analysis of NICS based Web Attack Detection for Advanced Intrusion Detection System.- A System for Traffic Events Detection using Fuzzy C-Means.- Multilingual Short Text Analysis of Twitter using Random Forest Approach.- Quality Assessment of Library Linked Data: A Case Study.- An Enhanced Meta-Model to Generate Web Forms for Ontology Population.- An Ontology-based Source Selection for Federated Query Processing: A Case Study.- OntoKnowNHS: Ontology driven Knowledge centric Novel Hybridised Semantic Scheme for Image Recommendation using Knowledge Graph.- The Covid-19 CODO Development Process: An Agile Approach to Knowledge Graph Development.- Selecting Ontologies for Reuse: Case of constructing Hotel Room Ontology.- Fabula: Hybridised Weightage based Book Recommendation System.- An Enhanced Personal Profile Ontology for Software Requirements Engineering Tasks Allocation.- Leveraging Enterprise Knowledge Graphs for Efficient Bridging Between Business Data with Large-scale Web Data.- Metadata Driven Semantically Aware Medical Query Expansion.- Property Assertion Constraints for an Informed, Error-Preventing Expansion of Knowledge Graphs.- Fake News Detection using Deep Learning.- Efficient Visual Sentiment Prediction approaches using deep learning models.- Uniform Textual Feedback Analysis for Effective Sentiment Analysis.- Towards Development of Knowledge Graph for Narrative Information in Medicine.- Automatic Text Summarization using Transformers.- Soft Computational Techniques to discover unique and precise knowledge from Big Data.