Introduction Samrómur Synthetic was developed by the Language and Voice Lab, Reykjavik University and contains 72 hours of Icelandic synthetic speech, transcripts and metadata. Source sentences were extracted from the Samrómur platform, comprised of texts and transcripts covering various genres. Text was processed through a text-to-speech system developed by Reykjavik University's Language and Voice Lab to generate speech files. Synthesized speech was created with 44 voices (22 male, 22 female) at four different speed rates for a total of 220 speakers and 62,700 utterances (with 285 sentences/speaker). Audio data is divided by speaker and is presented as flac compressed, single channel, 16 kHz, 16-bit linear PCM. Transcripts and metadata are presented in .tsv format.