List of Romanian counties by population presents the evolution of the resident population, by county, between 1948 and 2021. The table is ordered alphabetically, but can be sorted according to the results of each census. The National Institute of Statistics in Romania considered the following reference dates:

• 25 January 1948
• February 21, 1956
• March 15, 1966
• January 5, 1977
• January 7, 1992^{[n 1]}
• March 18, 2002^{[n 2]}
• October 20, 2011
• December 1, 2021^[1][2]

In each cell of the table, the number of the population and the demographic growth rate compared to the previous census are shown. The last column shows the population growth rate in the period 1948-2021.

Județ	Census population of:								1948- 2021
	1948	1956	1966	1977	1992	2002	2011	2021
Alba	361,062 ―	370,800 2.70%	382,786 3.23%	409,634 7.01%	414,227 1.05%	382,747 −7.53%	342,336 −10.55%	325,941 −4,80%	−9.73%
Arad	476,207 ―	475,620 −0.12%	481,248 1.18%	512,020 6.39%	487,370 −4.77%	461,791 −5.30%	412,235 −6.75%	410,143 −4.76%	−13.87%
Argeș	448,964 ―	483,741 7.75%	529,833 9.53%	631,918 19.27%	680,574 7.80%	652,625 −4.20%	612,431 −6.16%	569,932 −6.94%	26.94%
Bacău	414,996 ―	507,937 22.40%	598,321 17.79%	667,791 11.61%	736,078 10.44%	706,623 −4.19%	616,168 −12.8%	601,387 −2.40%	44.91%
Bihor	536,323 ―	574,488 7.12%	586,460 2.08%	633,094 7.95%	634,093 0.91%	600,246 −6.04%	575,398 −4.14%	551,297 −4.19%	2.79%
Bistrița-Năsăud	233,650 ―	255,789 9.48%	269,954 5.54%	286,628 6.18%	327,238 14.02%	311,657 −4.64%	301,425 −8.16%	295,988 3.41%	26.68%
Botoșani	385,236 ―	428,050 11.11%	452,406 5.69%	451,217 −0.26%	458,904 2.24%	452,834 −1.84%	404,429 −8.88%	392,821 −4.80%	1.97%
Brașov	300,836 ―	373,941 24.30%	442,692 18.39%	582,863 31.66%	642,513 10.36%	589,028 −8.43%	529,906 −6.76%	546,615 −0.47%	81.70%
Brăila	271,251 ―	297,276 9.59%	339,954 14.36%	377,954 11.18%	392,069 3.72%	373,174 −4.81%	316,652 −13.92%	281,452 −12.38%	3.76%
Buzău	430,225 ―	465,829 8.28%	480,951 3.25%	508,424 5.71%	516,307 1.68%	496,214 −4.01%	440,347 −9.10%	404,979 −10.22%	−5.87%
Caraș-Severin	302,254 ―	327,787 8.45%	358,726 9.44%	385,577 7.49%	375,794 −2.39%	333,219 −11.46%	287,535 −11.30%	246,588 −16.57%	−18.42%
Călărași	287,722 ―	318,573 10.72%	337,261 5.87%	338,807 0.46%	338,844 0.00%	324,617 −4.19%	287,269 −5.52%	283,458 −7.58%	−1.48%
Cluj	520,073 ―	580,344 11.59%	629,746 8.51%	715,507 13.62%	735,077 2.91%	702,755 −4.56%	691,106 −1.66%	679,141 −1.73%	30.59%
Constanța	311,062 ―	369,940 18.93%	465,752 25.90%	608,817 30.72%	748,044 22.99%	715,151 −4.49%	684,082 −4.34%	655,997 −4.11%	110.89%
Covasna	157,166 ―	172,509 9.76%	176,858 2.52%	199,017 12.53%	232,592 17.20%	222,449 −4.63%	211,254 −5.52%	200,042 −4.82%	27.28%
Dâmbovița	409,272 ―	438,985 7.26%	453,241 3.25%	527,620 16.41%	559,874 6.52%	541,763 −3.61%	510,287 −4.25%	479,404 −7.58%	17.14%
Dolj	615,301 ―	642,028 4.34%	691,116 7.65%	750,328 8.57%	761,074 1.57%	734,231 −3.66%	660,544 −10.04%	599,442 −9.25%	−2.58%
Galați	341,797 ―	396,138 15.90%	474,279 19.73%	581,561 22.62%	639,853 10.22%	619,556 −3.35%	530,612 −13.46%	496,892 −7.33%	45.38%
Giurgiu	313,793 ―	325,045 3.59%	320,120 −1.52%	327,494 2.30%	313,084 −4.32%	297,859 −4.94%	267,147 −5.52%	262,066 −6.88%	−16.48%
Gorj	280,524 ―	293,031 4.46%	298,382 1.83%	348,521 16.80%	400,100 15.06%	387,308 −3.42%	345,771 −11.80%	314,684 −7.88%	12.18%
Harghita	258,495 ―	273,964 5.98%	282,392 3.08%	326,310 15.55%	347,637 6.75%	326,222 −6.35%	304,765 −4.71%	291,950 −6.09%	12.94%
Hunedoara	306,955 ―	381,902 24.42%	474,602 24.27%	514,436 8.39%	547,993 6.51%	485,712 −11.36%	410,383 −13.82	361,657 −13.60%	17.82%
Ialomița	244,750 ―	274,655 12.22%	291,373 6.09%	295,965 1.58%	304,008 3.44%	296,572 −3.13%	265,559 −7.56%	250,816 −8.51%	2.48%
Iași	431,586 ―	516,635 19.71%	619,027 19.82%	729,243 17.80%	806,778 11.26%	816,910 0.69%	772,348 −5.45%	760,774 −1.50%	76.27%
Ilfov	167,533 ―	196,265 17.15%	229,773 17.07%	287,738 25.23%	286,939 −0.27%	300,123 4.59%	353,481 29.53%	542,686 39.61%	223.94%
Maramureș	321,287 ―	367,114 14.26%	427,645 16.49%	492,860 15.25%	538,534 9.58%	510,110 −5.55%	472,117 −6.17%	452,475 −5.47%	40.83%
Mehedinți	304,788 ―	304,091 −0.23%	310,021 1.95%	322,371 3.98%	332,091 3.20%	306,732 −7.80%	259,212 −13.48%	234,339 −11.70%	−23.11%
Mureș	461,403 ―	513,261 11.24%	561,598 9.42%	605,345 7.79%	607,298 0.78%	580,851 −4.79%	540,508 −5.17%	518,193 −5.93%	12.31%
Neamț	357,348 ―	419,949 17.52%	470,206 11.97%	532,096 13.16%	577,190 8.71%	554,516 −4.13%	507,399 −15.10%	454,203 −3.52%	27.10%
Olt	442,442 ―	458,982 3.74%	476,513 3.82%	518,804 8.88%	520,966 0.86%	489,274 −6.50%	421,769 −10.81%	383,280 −12.17%	−13.37%
Prahova	557,776 ―	623,817 11.84%	701,057 12.38%	817,168 16.56%	873,229 7.00%	829,945 −5.08%	762,886 −8.08%	695,117 −8.88%	24.62%
Satu Mare	312,672 ―	337,351 7.89%	359,393 6.53%	393,840 9.58%	400,158 1.76%	367,281 −8.36%	336,117 −6.24%	330,668 −3.98%	5.76%
Sălaj	262,580 ―	271,989 3.58%	263,103 −3.27%	264,569 0.56%	266,308 0.84%	248,015 −7.04%	225,631 −9.53%	212,224 −5.42%	−19.18%
Sibiu	335,116 ―	372,687 11.21%	414,756 11.29%	481,645 16.13%	452,820 −5.97%	421,724 −6.88%	377,273 −5.79%	388,325 −2.26%	15.88%
Suceava	439,751 ―	507,674 15.45%	572,781 12.82%	633,899 10.67%	700,799 10.72%	688,435 −1.91%	634,810 −7.79%	642,551 1.22%	46.12%
Teleorman	487,394 ―	510,488 4.74%	516,222 1.12%	518,943 0.53%	482,281 −6.76%	436,025 −9.88%	369,897 −12.82%	323,544 −14.88%	−33.62%
Timiș	588,936 ―	568,881 −3.41%	607,596 6.81%	696,884 14.70%	700,292 0.45%	677,926 −3.16%	683,540 0.83%	650,533 −4.83%	10.46%
Tulcea	192,228 ―	223,719 16.38%	236,709 5.81%	254,531 7.53%	270,197 6.47%	256,492 −5.35%	211,622 −16.92%	193,355 −9.26%	0.59%
Vaslui	344,917 ―	401,626 16.44%	431,555 7.45%	437,251 1.32%	457,799 5.52%	455,049 −1.37%	393,340 −13.09%	374,700 −5.26%	8.63%
Vâlcea	341,590 ―	362,356 6.08%	368,779 1.77%	414,241 12.33%	436,298 5.83%	413,247 −5.73%	374,240 −10.05%	335,312 −8.03%	0.08%
Vrancea	290,183 ―	326,532 12.53%	351,292 7.58%	369,740 5.25%	392,651 6.40%	387,632 −1.47%	339,510 −12.21%	341,861 −1.47%	15.55%
Municipiul București	1,025,180 ―	1,177,661 14.87%	1,366,684 16.05%	1,807,239 32.24%	2,067,545 14.40%	1,926,334 −6.83%	1,883,425 −2.23%	1,716,961 −8.84%	67.48%
Romania	15,872,624 ―	17,489,450 10.19%	19,103,163 9.23%	21,559,910 12.86%	22,760,449 5.80%	21,680,974 −4.95%	19,599,506 −7.19%	19,053,815 −5.31%	20.04%